KR20240134143A - Resist composition, resist pattern forming method, and compound - Google Patents

Abstract

식 중, R⁰¹ 은, 수소 원자 등이다. L⁰¹ 은, 2 가의 연결기이다. Ra⁰¹ 및 Ra⁰² 는, 각각 독립적으로, 치환기를 가져도 되는 탄화수소기이다. Ar⁰¹ 은, 수소 원자의 일부 또는 전부가 요오드 원자로 치환되어 있는 아릴기 등이다. 상기 아릴기는, 요오드 원자 이외의 치환기를 가져도 된다.A resist composition containing a resin component (A1) having a structural unit (a01) derived from a compound represented by the general formula (a0-1).

In the formula, R ⁰¹ is a hydrogen atom, etc. L ⁰¹ is a divalent linking group. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, etc. The aryl group may have a substituent other than an iodine atom.

Description

Resist composition, resist pattern forming method, and compound

The present invention relates to a resist composition, a method for forming a resist pattern, and a compound.

This application claims priority from Japanese Patent Application No. 2022-007875, filed in Japan on January 21, 2022, the contents of which are incorporated herein.

Recently, in the manufacture of semiconductor devices and liquid crystal display devices, the pattern miniaturization is progressing rapidly due to the advancement of lithography technology. As a method of miniaturization, the wavelength of the exposure light source is generally shortened (higher energy).

Resist materials are required to have lithographic characteristics such as sensitivity to these exposure light sources and resolution to reproduce fine dimensional patterns.

As a resist material satisfying such requirements, a chemically amplified resist composition containing a substrate component whose solubility in a developer changes by the action of an acid and an acid generator component that generates acid by exposure has been conventionally used.

In chemically amplified resist compositions, resins having multiple constituent units are generally used to improve lithography characteristics, etc.

For example, Patent Document 1 discloses a resist composition containing a resin component (A1) having a structural unit (a01) having a specific acid-labile group, a structural unit (a02) including a cyclic group in which -O-C(=O)- forms a part of a ring skeleton (however, excluding those forming a cross-linked structure), and a specific structural unit (a03) having a hydroxyl group. This resist composition is disclosed as controlling acid diffusion, improving affinity for a developer, and having excellent sensitivity, roughness reduction, and resolution.

Japanese Patent Publication No. 2020-085916

With further advancements in lithography technology, expansion of application fields, etc., patterns are rapidly becoming finer. And, along with this, when manufacturing semiconductor devices, etc., a technology that can form fine patterns in a good shape is required.

However, in response to these demands, the conventional resist composition described in Patent Document 1 does not necessarily sufficiently achieve both sensitivity in resist pattern formation and reduction of roughness, and thus, compatibility at a higher level is required.

The present invention has been made in consideration of the above circumstances, and has as its object the provision of a resist composition capable of achieving high sensitivity and forming a resist pattern having excellent roughness reduction, a method for forming a resist pattern using the resist composition, and a compound capable of producing a resin contained in the resist composition.

To solve the above problem, the present invention adopts the following configuration.

That is, the first aspect of the present invention is a resist composition that generates an acid upon exposure and further changes its solubility in a developer by the action of the acid, the resist composition containing a resin component (A1) having a structural unit (a01) derived from a compound represented by the following general formula (a0-1).

[Chemical Formula 1]

[In the formula, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰¹ is a divalent linking group. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced by iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced by iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.]

A second aspect of the present invention is a method for forming a resist pattern, comprising the steps of forming a resist film on a support using a resist composition related to the first aspect, exposing the resist film, and developing the exposed resist film to form a resist pattern.

The third aspect of the present invention is a compound represented by the general formula (a0-1).

According to the present invention, it is possible to provide a resist composition capable of achieving high sensitivity and forming a resist pattern having excellent roughness reduction, a method for forming a resist pattern using the resist composition, and a compound capable of producing a resin contained in the resist composition.

In the scope of this specification and the claims of this patent, “aliphatic” is defined as a relative concept to aromatic, and means a group, compound, etc. that does not have aromaticity.

"Alkyl group", unless otherwise specified, includes linear, branched, and cyclic monovalent saturated hydrocarbon groups. The same applies to alkyl groups among alkoxy groups.

“Alkylene group”, unless otherwise specified, includes linear, branched, and cyclic divalent saturated hydrocarbon groups.

"Halogen atoms" include fluorine atoms, chlorine atoms, bromine atoms, and iodine atoms.

“Component unit” refers to a monomer unit (monomer unit) that constitutes a polymer compound (resin, polymer, copolymer).

When it is described as “may have a substituent,” it includes both the case where a hydrogen atom (-H) is replaced with a monovalent group and the case where a methylene group (-CH ₂ -) is replaced with a divalent group.

“Exposure” is a concept that includes all exposure to radiation.

An “acid-decomposable group” is a group having acid decomposability in which at least a portion of the bonds in the structure of the acid-decomposable group can be cleaved by the action of an acid.

As an acid-decomposable group whose polarity increases by the action of an acid, an example of such a group is a group that decomposes by the action of an acid to produce a polar group.

Polar groups include, for example, carboxyl groups, hydroxyl groups, amino groups, and sulfo groups (-SO ₃ H).

More specifically, as an acid-dissociable group, a group in which the polar group is protected by an acid-dissociable group (for example, a group in which a hydrogen atom of an OH-containing polar group is protected by an acid-dissociable group) can be mentioned.

The term “acid-dissociable group” refers to (i) a group having acid dissociability, which can cause cleavage of a bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group by the action of an acid, or (ii) a group in which, after some of the bonds have been cleaved by the action of an acid, a decarboxylation reaction further occurs, causing cleavage of the bond between the acid-dissociable group and an atom adjacent to the acid-dissociable group.

The acid-dissociable group constituting the acid-decomposable group must have a lower polarity than the polar group generated by the dissociation of the acid-dissociable group, and thus, when the acid-dissociable group is dissociated by the action of an acid, a polar group having a higher polarity than the acid-dissociable group is generated, thereby increasing the polarity. As a result, the polarity of the entire (A1) component increases. As the polarity increases, the solubility in the developer relatively changes, and when the developer is an alkaline developer, the solubility increases, and when the developer is an organic developer, the solubility decreases.

The "base component" is an organic compound having film-forming ability. The organic compounds used as the base component are broadly classified into non-polymers and polymers. As a non-polymer, one having a molecular weight of 500 or more and less than 4000 is usually used. Hereinafter, when referred to as a "low-molecular-weight compound", a non-polymer having a molecular weight of 500 or more and less than 4000 is indicated. As a polymer, one having a molecular weight of 1000 or more is usually used. Hereinafter, when referred to as a "resin", "high-molecular-weight compound" or "polymer", a polymer having a molecular weight of 1000 or more is indicated. As the molecular weight of the polymer, the weight average molecular weight converted to polystyrene by GPC (gel permeation chromatography) is used.

“Derived structural unit” means a structural unit formed by cleavage of multiple bonds between carbon atoms, for example, ethylenic double bonds.

"Acrylic acid ester" may have a hydrogen atom bonded to the carbon atom at the α-position replaced by a substituent. The substituent (R ^αx ) replacing the hydrogen atom bonded to the carbon atom at the α-position is an atom or group other than a hydrogen atom. In addition, it also includes an itaconic acid diester in which the substituent (R ^αx ) is replaced by a substituent containing an ester bond, or an α hydroxyacrylic ester in which the substituent (R ^αx ) is replaced by a hydroxyalkyl group or a group modifying the hydroxyl group. In addition, the carbon atom at the α-position of the acrylic acid ester is a carbon atom to which the carbonyl group of acrylic acid is bonded, unless otherwise specified.

Hereinafter, an acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α position is substituted with a substituent is sometimes called an α-substituted acrylic acid ester.

The term "derivative" refers to a compound in which the hydrogen atom at the α-position of the target compound is replaced by another substituent such as an alkyl group or a halogenated alkyl group, and derivatives thereof. Examples of such derivatives include a compound in which the hydrogen atom of a hydroxyl group of the target compound, which may be substituted by a substituent at the α-position, is replaced by an organic group; a compound in which a substituent other than a hydroxyl group is bonded to the target compound, which may be substituted by a substituent at the α-position, etc. In addition, unless otherwise specified, the α-position refers to the 1st carbon atom adjacent to a functional group.

As a substituent that replaces the hydrogen atom at the α position of hydroxystyrene, the same as R ^αx can be mentioned.

In the scope of this specification and the claims of this patent, depending on the structure represented by the chemical formula, there may be a substituent carbon present, and enantiomers or diastereo isomers may exist. In such a case, these isomers are represented by a single chemical formula. These isomers may be used alone or as a mixture.

(Resist composition)

The resist composition of the present embodiment generates acid upon exposure, and further, its solubility in a developer changes due to the action of the acid.

These resist compositions contain a base component (A) (hereinafter also referred to as “component (A)”) whose solubility in a developer changes by the action of an acid.

In the resist composition of the present embodiment, component (A) may generate acid upon exposure, or an additive component formulated separately from component (A) may generate acid upon exposure.

The resist composition of the present embodiment may specifically (1) additionally contain an acid generator component (B) that generates acid upon exposure (hereinafter referred to as “component (B)”); (2) component (A) may be a component that generates acid upon exposure; and (3) component (A) may be a component that generates acid upon exposure and further contain component (B).

That is, in the cases of (2) and (3) above, component (A) is a "base component that generates an acid upon exposure and further changes its solubility in a developer solution by the action of the acid." When component (A) is a base component that generates an acid upon exposure and further changes its solubility in a developer solution by the action of the acid, it is preferable that component (A1) described below is a resin that generates an acid upon exposure and further changes its solubility in a developer solution by the action of the acid. As such a resin, a polymer compound having a structural unit that generates an acid upon exposure can be used. As the structural unit that generates an acid upon exposure, a known one can be used.

Among the above, it is preferable that the resist composition of the present embodiment is the case of the above (1). That is, it is preferable that the resist composition of the present embodiment contains component (A) and component (B).

When a resist film is formed using the resist composition of the present embodiment and selective exposure is performed on the resist film, in the exposed portion of the resist film, for example, acid is generated from component (B), and the solubility of component (A) in a developing solution changes due to the action of the acid, whereas in the unexposed portion of the resist film, the solubility of component (A) in a developing solution does not change, so a difference in solubility in a developing solution occurs between the exposed portion and the unexposed portion. Therefore, when the resist film is developed, if the resist composition is positive, the exposed portion of the resist film is dissolved and removed, forming a positive resist pattern, and if the resist composition is negative, the unexposed portion of the resist film is dissolved and removed, forming a negative resist pattern.

The resist composition of the present embodiment may be a positive resist composition or a negative resist composition. In addition, the resist composition of the present embodiment may be for an alkaline developing process that uses an alkaline developer for the developing treatment at the time of forming a resist pattern, or may be for a solvent developing process that uses a developer containing an organic solvent (organic developer) for the developing treatment.

＜(A) Component＞

In the resist composition of the present embodiment, component (A) includes a resin component (A1) whose solubility in a developer changes by the action of an acid (hereinafter also referred to as “component (A1)”).

(A1) By using the component, since the polarity of the substrate component changes before and after exposure, good development contrast can be obtained not only in the alkaline development process but also in the solvent development process.

As for the (A) component, other high molecular weight compounds and/or low molecular weight compounds may be used together with the (A1) component.

In the resist composition of the present embodiment, component (A) may be used alone or in combination of two or more types.

· (A1) About the ingredients

(A1) The component is a resin component whose solubility in a developer changes due to the action of an acid.

(A1) The component has a structural unit (a01) derived from a compound represented by the following general formula (a0-1).

(A1) In addition to the constituent unit (a01), the component may have other constituent units as needed.

[Chemical formula 2]

[In the formula, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰¹ is a divalent linking group. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced by iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced by iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.]

In the above general formula (a0-1), R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms.

The alkyl group having 1 to 10 carbon atoms in R ⁰¹ is preferably a linear or branched alkyl group having 1 to 10 carbon atoms, and more preferably a linear or branched alkyl group having 1 to 5 carbon atoms. Specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like.

A halogenated alkyl group having 1 to 10 carbon atoms is a group in which some or all of the hydrogen atoms of the alkyl group having 1 to 10 carbon atoms are replaced with halogen atoms. As the halogen atom, a fluorine atom is particularly preferable.

As R ⁰¹ , a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of ease of industrial availability, a hydrogen atom or a methyl group is more preferable.

In the above general formula (a0-1), L ⁰¹ may include, as a divalent linking group, a divalent hydrocarbon group which may have a substituent, and a divalent linking group containing a hetero atom.

· Divalent hydrocarbon group which may have a substituent:

When L ⁰¹ is a divalent hydrocarbon group that may have a substituent, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group.

·· Aliphatic hydrocarbon group in L ⁰¹

An aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. The aliphatic hydrocarbon group may be saturated or unsaturated, and saturated is usually preferred.

The above aliphatic hydrocarbon group may include a linear or branched aliphatic hydrocarbon group, or an aliphatic hydrocarbon group containing a ring in its structure.

··· A straight or branched aliphatic hydrocarbon group

The linear aliphatic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and most preferably 1 to 3 carbon atoms.

As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specific examples thereof include a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [-(CH ₂ ) ₃ -], a tetramethylene group [-(CH ₂ ) ₄ -], a pentamethylene group [-(CH ₂ ) ₅ -], and the like.

The branched-chain aliphatic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6 carbon atoms, still more preferably 3 or 4 carbon atoms, and most preferably 3 carbon atoms.

As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferable, and specifically, alkylmethylene groups such as -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ -; alkylethylene groups such as -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ CH ₃ ) ₂ -CH ₂ -; Examples thereof include alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -, and the like; alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

The above linear or branched aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include a fluorine atom, a fluorinated alkyl group having 1 to 5 carbon atoms substituted with a fluorine atom, a carbonyl group, etc.

··· Aliphatic hydrocarbon group containing a ring in the structure

Examples of the aliphatic hydrocarbon group containing a ring in the structure include a cyclic aliphatic hydrocarbon group (a group in which two hydrogen atoms are removed from an aliphatic hydrocarbon ring) that may include a substituent containing a hetero atom in the ring structure, a group in which the cyclic aliphatic hydrocarbon group is bonded to the terminal of a linear or branched aliphatic hydrocarbon group, a group in which the cyclic aliphatic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group, and the like. Examples of the linear or branched aliphatic hydrocarbon group include the same ones as described above.

The cyclic aliphatic hydrocarbon group preferably has 3 to 20 carbon atoms, more preferably 3 to 12 carbon atoms.

The cyclic aliphatic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a monocycloalkane is preferable. As the monocycloalkane, a group having 3 to 6 carbon atoms is preferable, and specific examples thereof include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing two hydrogen atoms from a polycycloalkane is preferable, and as the polycycloalkane, a group having 7 to 12 carbon atoms is preferable, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

The cyclic aliphatic hydrocarbon group may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, etc.

As the alkyl group as the above substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable.

As the alkoxy group as the above substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group is more preferable, and a methoxy group and an ethoxy group are still more preferable.

As the halogen atom as the above substituent, a fluorine atom is preferable.

As the halogenated alkyl group as the above substituent, a group in which some or all of the hydrogen atoms of the alkyl group are replaced with the halogen atoms can be exemplified.

A cyclic aliphatic hydrocarbon group may have some of the carbon atoms constituting the ring structure replaced by a substituent containing a hetero atom. Preferred substituents containing the hetero atom are -O-, -C(=O)-O-, -S-, -S(=O) ₂ -, -S(=O) ₂ -O-.

In addition, the cyclic aliphatic hydrocarbon group may be a lactone-containing cyclic group such as a group represented by the following general formulae (L-r-1) to (L-r-7).

[Chemical Formula 3]

[In the formula, Ra' ⁰²¹ is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR ⁰ ", -OC(=O)R ⁰ ", a hydroxyalkyl group, or a cyano group; R ⁰ " is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; A ⁰ " is an alkylene group having 1 to 5 carbon atoms which may include an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, n0' is an integer of 0 to 2, and m0' is 0 or 1. * represents a bond with the carbon atom to which R ⁰¹ in the general formula (a0-1) is bonded. ** represents a bond with the carbonyl group in the general formula (a0-1).]

Among the above general formulas (Lr-1) to (Lr-7), the alkyl group in Ra' ⁰²¹ is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched.

As the alkoxy group in Ra' ⁰²¹ , an alkoxy group having 1 to 6 carbon atoms is preferable. The alkoxy group is preferably linear or branched. Specifically, a group in which an alkyl group exemplified as the alkyl group in the above Ra' ⁰²¹ and an oxygen atom (-O-) are connected can be exemplified.

As the halogen atom in Ra' ⁰²¹ , a fluorine atom is preferable.

As the halogenated alkyl group in Ra' ⁰²¹ , a group in which some or all of the hydrogen atoms of the alkyl group in Ra' ⁰²¹ are replaced with the halogen atoms can be exemplified. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In -COOR ⁰ ", -OC(=O)R ⁰ " in Ra' ⁰²¹ , R ⁰ " is all a hydrogen atom, an alkyl group, and a lactone-containing cyclic group.

The alkyl group in "R ⁰ " may be any of a linear, branched, or cyclic type, and the number of carbon atoms is preferably 1 to 15.

When R ⁰ " is a linear or branched alkyl group, it is preferably one having 1 to 10 carbon atoms, more preferably one having 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group.

When R ⁰ " is a cyclic alkyl group, it is preferably one having 3 to 15 carbon atoms, more preferably one having 4 to 12 carbon atoms, and most preferably one having 5 to 10 carbon atoms.

As the lactone-containing cyclic group in "R ⁰ ", the same groups as those represented by the general formulae (Lr-1) to (Lr-7) can be exemplified.

As the hydroxyalkyl group in Ra' ⁰²¹ , a group having 1 to 6 carbon atoms is preferable, and specifically, a group in which at least one hydrogen atom of the alkyl group in Ra' ⁰²¹ is replaced with a hydroxyl group can be mentioned.

Among the above general formulas (Lr-2), (Lr-3), and (Lr-5), the alkylene group having 1 to 5 carbon atoms in A ⁰ "is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which -O- or -S- is interposed between the terminals or carbon atoms of the alkylene group, and examples thereof include -O-CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH ₂ -, and the like. As A ⁰ ", an alkylene group having 1 to 5 carbon atoms or -O- is preferable.

·· Aromatic hydrocarbon group in L ⁰¹

The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

This aromatic ring is not particularly limited as long as it is a ring-shaped conjugated system having 4n + 2 π electrons, and may be a monocyclic ring or a polycyclic ring. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the carbon atoms do not include the carbon atoms in the substituent.

Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced with heteroatoms. Examples of the heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include a pyridine ring, a thiophene ring, and the like.

As an aromatic hydrocarbon group, examples thereof include a group in which two hydrogen atoms are removed from the aromatic hydrocarbon ring or aromatic heterocycle (an arylene group or a heteroarylene group); a group in which two hydrogen atoms are removed from an aromatic compound (e.g., biphenyl, fluorene, etc.) containing two or more aromatic rings; a group in which one of the hydrogen atoms of a group in which one hydrogen atom is removed from the aromatic hydrocarbon ring or aromatic heterocycle (an aryl group or a heteroaryl group) is substituted with an alkylene group (e.g., a group in which one hydrogen atom is additionally removed from an aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group bonded to the above aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

The above aromatic hydrocarbon group may have a hydrogen atom of the aromatic hydrocarbon group replaced by a substituent. For example, a hydrogen atom bonded to an aromatic ring in the aromatic hydrocarbon group may be replaced by a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and the like.

As the alkyl group as the above substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, or a tert-butyl group is more preferable.

As the alkoxy group, halogen atom and halogenated alkyl group as the above substituent, examples thereof include those as substituents that substitute hydrogen atoms of the above cyclic aliphatic hydrocarbon group.

· Bivalent linking group containing heteroatoms:

When L ⁰¹ is a divalent linking group containing a hetero atom, preferable ones as the linking group are -O-, -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -NH-C(=NH)- (H may be substituted with a substituent such as an alkyl group or an acyl group), -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, general formula -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-OY ²¹ -, -[Y ²¹ -C(=O)-O] _m" -Y ²² -, -Y ²¹ -OC(=O)-Y ²² - or -Y ²¹ Examples thereof include a group represented by -S(=O) ₂ -OY ²² - [wherein Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent, O is an oxygen atom, and m" is an integer from 0 to 3.]

When the divalent linking group containing the above hetero atom is -C(=O)-NH-, -C(=O)-NH-C(=O)-, -NH-, -NH-C(=NH)-, the H may be substituted with a substituent such as an alkyl group or an acyl group. The substituent (alkyl group, acyl group, etc.) preferably has 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, and particularly preferably 1 to 5 carbon atoms.

In the general formulas -Y ²¹ -OY ²² -, -Y ²¹ -O-, -Y ²¹ -C(=O)-O-, -C(=O)-OY ²¹ -, -[Y ²¹ -C(=O)-O] _m" -Y ²² -, -Y ²¹ -OC(=O)-Y ²² - or -Y ²¹ -S(=O) ₂ -OY ²² -, Y ²¹ and Y ²² are each independently a divalent hydrocarbon group which may have a substituent. Examples of the divalent hydrocarbon group include the same as (the divalent hydrocarbon group which may have a substituent) exemplified in the explanation of the divalent linking group in L ⁰¹ above.

As Y ²¹ , a linear aliphatic hydrocarbon group is preferable, a linear alkylene group is more preferable, a linear alkylene group having 1 to 5 carbon atoms is still more preferable, and a methylene group or an ethylene group is particularly preferable.

As Y ²² , a linear or branched aliphatic hydrocarbon group is preferable, and a methylene group, an ethylene group or an alkylmethylene group is more preferable. The alkyl group in the alkylmethylene group is preferably a linear alkyl group having 1 to 5 carbon atoms, more preferably a linear alkyl group having 1 to 3 carbon atoms, and most preferably a methyl group.

In the group represented by the formula -[Y ²¹ -C(=O)-O] _m" -Y ²² -, m" is an integer of 0 to 3, preferably an integer of 0 to 2, more preferably 0 or 1, and particularly preferably 1. In short, among the groups represented by the formula -[Y ²¹ -C(=O)-O] _m" -Y ²² -, a group represented by the formula -Y ²¹ -C(=O)-OY ²² - is particularly preferable. Among these, a group represented by the formula -(CH ₂ ) _a' -C(=O)-O-(CH ₂ ) _b ' - is preferable. In the formula, a' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1. b' is an integer of 1 to 10, preferably an integer of 1 to 8, more preferably an integer of 1 to 5, still more preferably 1 or 2, and most preferably 1.

Among the above, L ⁰¹ is preferably a divalent linking group having a group composed of an ester bond [-C(=O)-O-, -OC(=O)-], an aromatic hydrocarbon group, a lactone-containing cyclic group, or a combination of these.

More specifically, L ⁰¹ is preferably a group composed of an ester bond and an alkylene group, an aromatic hydrocarbon group, or a group composed of an ester bond and a lactone-containing cyclic group.

In the group consisting of the ester bond and the alkylene group, the alkylene group is preferably a linear or branched alkylene group having 1 to 5 carbon atoms, more preferably a linear alkylene group having 1 to 5 carbon atoms, and still more preferably a methylene group or an ethylene group.

In addition, the alkylene group may have a substituent. The substituent may include an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, etc.

The aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

This aromatic ring is not particularly limited as long as it is a ring-shaped conjugated system having 4n + 2 π electrons, and may be a monocyclic ring or a polycyclic ring. The aromatic ring preferably has 5 to 30 carbon atoms, more preferably 5 to 20 carbon atoms, still more preferably 6 to 15 carbon atoms, and particularly preferably 6 to 12 carbon atoms. However, the carbon atoms do not include the carbon atoms in the substituent.

Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced with heteroatoms. Examples of the heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include a pyridine ring, a thiophene ring, and the like.

Specific examples of the aromatic hydrocarbon group include a group in which two hydrogen atoms are removed from the aromatic hydrocarbon ring or aromatic heterocycle (an arylene group or a heteroarylene group); a group in which two hydrogen atoms are removed from an aromatic compound (e.g., biphenyl, fluorene, etc.) containing two or more aromatic rings; a group in which one of the hydrogen atoms of the group in which one hydrogen atom is removed from the aromatic hydrocarbon ring or aromatic heterocycle (an aryl group or a heteroaryl group) is substituted with an alkylene group (e.g., a group in which one hydrogen atom is additionally removed from the aryl group in an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group). The number of carbon atoms in the alkylene group bonded to the above aryl group or heteroaryl group is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

In addition, the aromatic hydrocarbon group may have a substituent. The substituent may include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, etc.

Among the above, the aromatic hydrocarbon group is preferably an arylene group which may have a substituent, more preferably an arylene group having a substituent, still more preferably an arylene group having a hydroxyl group, and particularly preferably a phenylene group having a hydroxyl group.

As the lactone-containing cyclic group in the group consisting of an ester bond and a lactone-containing cyclic group, groups represented by the general formulae (L-r-1) to (L-r-7) are preferable, and groups represented by the general formula (L-r-2) are more preferable.

Among the above, L ⁰¹ is preferably a group represented by the following general formulas (L0-r-1) to (L0-r-5).

[Chemical Formula 4]

[In the formula, Rx ⁰⁰ is, each independently, an alkylene group. Ar ⁰⁰ is an arylene group which may have a substituent. Lc ⁰⁰ is a lactone-containing cyclic group represented by any one of the general formulas (Lr-1) to (Lr-7). * represents a bond with the carbon atom to which R ⁰¹ in the general formula (a0-1) is bonded. ** represents a bond with the carbon atom of the carbonyl group in the general formula (a0-1).]

It is preferable that Rx ⁰⁰ is an alkylene group having 1 to 5 carbon atoms.

Ar ⁰⁰ is preferably an arylene group which may have a substituent, more preferably an arylene group having a hydroxyl group, and even more preferably a phenylene group having a hydroxyl group.

Lc ⁰⁰ is a lactone-containing cyclic group represented by any one of the general formulas (Lr-1) to (Lr-7), and is preferably a lactone-containing cyclic group represented by the general formula (Lr-2).

Among the above, L ⁰¹ is preferably a group represented by any one of the general formulas (L0-r-3) to (L0-r-5), and is more preferably a group represented by the general formula (L0-r-3).

Among the above general formulas (a0-1), the hydrocarbon groups in Ra ⁰¹ and Ra ⁰² include linear and branched hydrocarbon groups and cyclic hydrocarbon groups.

Examples of linear or branched hydrocarbon groups include linear or branched saturated hydrocarbon groups (alkyl groups), or linear or branched unsaturated hydrocarbon groups.

Specific examples of the linear or branched alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like.

As the linear or branched unsaturated hydrocarbon group, more specifically, examples thereof include an unsaturated hydrocarbon group having a double bond, such as an alkenyl group, an alkadienyl group, or an alkatrienyl group; an unsaturated hydrocarbon group having a triple bond, such as an alkynyl group, a group obtained by removing one hydrogen atom from a dialkyne, or a group obtained by removing one hydrogen atom from a trialkyne.

Specific examples of the linear or branched alkenyl group include linear alkenyl groups such as a vinyl group, a propenyl group (allyl group), and a 2-butenyl group; and branched alkenyl groups such as a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.

Specific examples of the alkadienyl group include a propadienyl group and a butadienyl group.

Specific examples of the alkaline trienyl group include a butatrienyl group, etc.

Specific examples of the linear or branched alkynyl group include linear alkynyl groups such as an ethynyl group, a propargyl group, and a 3-pentynyl group; and branched alkynyl groups such as a 1-methylpropargyl group.

Specific examples of groups in which one hydrogen atom has been removed from dialkyne include groups in which one hydrogen atom has been removed from diacetylene.

A specific example of a group in which one hydrogen atom has been removed from the trialkyne includes a group in which one hydrogen atom has been removed from hexa-1,3,5-triyne.

The cyclic hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may also be a polycyclic group or a monocyclic group.

As the aliphatic hydrocarbon group which is a monocyclic group, a group in which one hydrogen atom is removed from a monocycloalkane is preferable. As the monocycloalkane, a group having 3 to 6 carbon atoms is preferable, and a specific example thereof is cyclopropane.

As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable, and as the polycycloalkane, a group having 7 to 12 carbon atoms is preferable, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

As the aromatic hydrocarbon group, an aryl group or a heteroaryl group can be mentioned, and specifically, a phenyl group, a naphthyl group, etc. can be mentioned.

Substituents that the hydrocarbon group in Ra ⁰¹ and Ra ⁰² may have include, for example, -R ^P1 , -R ^P2 -OR ^P1 , -R ^P2 -CO-R ^P1 , -R ^P2 -CO-OR ^P1 , -R ^P2 -O-CO-R ^P1 , -R ^P2 -OH, -R ^P2 -CN or -R ^P2 -COOH (hereinafter, these substituents are collectively referred to as "Ra ^x5 ").

Here, R ^P1 is a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 30 carbon atoms. In addition, R ^P2 is a single bond, a divalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms, a divalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 30 carbon atoms. However, some or all of the hydrogen atoms contained in the chain-like saturated hydrocarbon group, the aliphatic cyclic saturated hydrocarbon group, and the aromatic hydrocarbon group of R ^P1 and R ^P2 may be replaced with fluorine atoms. The above aliphatic cyclic hydrocarbon group may have one or more of the above substituents alone, or may have one or more of each of the above substituents.

Examples of monovalent chain-shaped saturated hydrocarbon groups having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, etc.

Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; and polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group.

Examples of monovalent aromatic hydrocarbon groups having 6 to 30 carbon atoms include groups in which one hydrogen atom is removed from an aromatic hydrocarbon ring, such as benzene, biphenyl, fluorene, naphthalene, anthracene, and phenanthrene.

Among the above general formulas (a0-1), Ra ⁰¹ and Ra ⁰² are each independently preferably a linear or branched saturated hydrocarbon group, or a linear or branched unsaturated hydrocarbon group, more preferably a linear or branched saturated hydrocarbon group having 1 to 5 carbon atoms, or a linear or branched unsaturated hydrocarbon group having 1 to 5 carbon atoms, still more preferably a linear saturated hydrocarbon group having 1 to 5 carbon atoms, or a linear unsaturated hydrocarbon group having 1 to 5 carbon atoms, and particularly preferably a methyl group, an ethyl group, an ethynyl group, or a vinyl group.

More specifically, it is preferable that both Ra ⁰¹ and Ra ⁰² are a methyl group or an ethyl group, or that Ra ⁰¹ is a methyl group or an ethyl group and Ra ⁰² is an ethynyl group or a vinyl group.

In the above general formula (a0-1), Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms.

The aryl group in Ar ⁰¹ may be a group in which one hydrogen atom has been removed from an aromatic ring. Examples of the aromatic ring include benzene, naphthalene, anthracene, and phenanthrene.

As the aryl group in Ar ⁰¹ , specifically, a phenyl group is preferable.

As a heteroaryl group in Ar ⁰¹ , a group in which one hydrogen atom is removed from an aromatic heterocyclic ring can be mentioned. Examples of the aromatic heterocyclic ring include a pyridine ring and a thiophene ring.

As the heteroaryl group in Ar ⁰¹ , a thiophenyl group is specifically preferred.

Some or all of the hydrogen atoms of the aryl group and heteroaryl group in Ar ⁰¹ are replaced with iodine atoms.

The number of iodine atoms is preferably 1 to 5, more preferably 1 to 3, still more preferably 2 or 3, and particularly preferably 3.

The aryl group and heteroaryl group in Ar ⁰¹ may have a substituent other than an iodine atom. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, and the like.

Among the above general formulas (a0-1), Ar ⁰¹ is preferably an aryl group having 1 to 3 iodine atoms, or a heteroaryl group having 1 to 3 iodine atoms, more preferably an aryl group having 1 to 3 iodine atoms, and even more preferably a phenyl group having 1 to 3 iodine atoms.

Among the above, it is preferable that the constituent unit (a01) is a constituent unit (a011) derived from a compound represented by the following general formula (a0-1-1).

[Chemical Formula 5]

[Wherein, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰⁰¹ is a divalent linking group having an ester bond, an aromatic hydrocarbon group, a lactone-containing cyclic group, or a group consisting of a combination of these. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.]

In the above general formula (a0-1-1), R ⁰¹ , Ra ⁰¹ , Ra ⁰² and Ar ⁰¹ are each identical to R ⁰¹ , Ra ⁰¹ , Ra ⁰² and Ar ⁰¹ in the above-described general formula (a0-1).

In the above general formula (a0-1-1), L ⁰⁰¹ is a divalent linking group having a group composed of an ester bond, an aromatic hydrocarbon group, a lactone-containing cyclic group, or a combination thereof. As the divalent linking group, examples thereof include the same divalent linking groups as those in L ⁰¹ in the above-described general formula (a0-1) having a group composed of an ester bond, an aromatic hydrocarbon group, a lactone-containing cyclic group, or a combination thereof.

Among the above general formula (a0-1-1), L ⁰⁰¹ is preferably any of the groups represented by the above general formulas (L0-r-1) to (L0-r-5), more preferably any of the groups represented by the above general formulas (L0-r-3) to (L0-r-5), and more preferably a group represented by the above general formula (L0-r-3).

Specific examples of compounds represented by the general formula (a0-1) are shown below.

[Chemical formula 6]

[Chemical formula 7]

In the resist composition of the present embodiment, the structural unit (a01) is preferably a structural unit derived from a compound represented by any one of the chemical formulas (a01-01-1) to (a01-01-18), more preferably a structural unit derived from a compound represented by any one of the chemical formulas (a01-01-2) to (a01-01-9), still more preferably a structural unit derived from a compound represented by the chemical formula (a01-01-6), (a01-01-8), or (a01-01-9), and particularly preferably a structural unit derived from a compound represented by the chemical formula (a01-01-8) or (a01-01-9).

(A1) The proportion of the structural unit (a01) among the components is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and still more preferably 40 to 60 mol%, with respect to the total (100 mol%) of all structural units constituting the (A1) component.

By setting the ratio of the constituent unit (a01) to the lower limit of the above-described preferable range or higher, the sensitivity and roughness reduction are further improved. On the other hand, when it is equal to or lower than the upper limit of the above-described preferable range, that is, when the (A1) component has a constituent unit other than the constituent unit (a01), the lithography characteristics can be further improved by the balance with the other constituent units described below.

≪Other components≫

(A1) In addition to the above-described structural unit (a01), the component may have other structural units as needed.

Other structural units include, for example, a structural unit (a1) including an acid-decomposable group whose polarity increases by the action of an acid; a structural unit (a10) represented by the general formula (a10-1) described below; a structural unit (a2) including a lactone-containing cyclic group; and a structural unit (a8) derived from a compound represented by the general formula (a8-1) described below.

In addition, for other composition units, those corresponding to the composition unit (a01) described above are excluded.

≪Composition Unit (a1)≫

The constituent unit (a1) is a constituent unit including an acid-decomposable group whose polarity increases by the action of an acid.

However, the components corresponding to the above-described component unit (a01) are excluded.

As for acid dissociation groups, those proposed so far as acid dissociation groups of base resins for chemically amplified resist compositions can be mentioned.

Specific examples of acid-dissociable groups proposed as base resins for chemically amplified resist compositions include the “acetal-type acid-dissociable group,” the “tertiary alkyl ester-type acid-dissociable group,” the “tertiary alkyloxycarbonyl acid-dissociable group,” and the “secondary alkyl ester-type acid-dissociable group,” which are described below.

Acetal type acid dissociation group:

As an acid-labile group protecting a carboxyl group or a hydroxyl group among the above polar groups, an acid-labile group represented by the following general formula (a1-r-1) (hereinafter sometimes referred to as an “acetal-type acid-labile group”) can be mentioned, for example.

[Chemical formula 8]

[In the formula, Ra' ¹ and Ra' ² are hydrogen atoms or alkyl groups. Ra' ³ is a hydrocarbon group, and Ra' ³ may form a ring by combining with either Ra' ¹ or Ra' ^2. ]

In the formula (a1-r-1), it is preferable that at least one of Ra' ¹ and Ra' ² is a hydrogen atom, and it is more preferable that both are hydrogen atoms.

When Ra' ¹ or Ra' ² is an alkyl group, examples of the alkyl group include the same alkyl groups as those exemplified as substituents which may be bonded to the carbon atom at the α position in the description of the above-mentioned α-substituted acrylic acid ester, and an alkyl group having 1 to 5 carbon atoms is preferable. Specifically, a linear or branched alkyl group is preferable. More specifically, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like can be mentioned, and a methyl group or an ethyl group is more preferable, and a methyl group is particularly preferable.

In the formula (a1-r-1), the hydrocarbon group of Ra' ³ may include a linear or branched alkyl group, or a cyclic hydrocarbon group.

The linear alkyl group preferably has 1 to 5 carbon atoms, more preferably 1 to 4 carbon atoms, and even more preferably 1 or 2 carbon atoms. Specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and the like can be mentioned. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

The branched alkyl group preferably has 3 to 10 carbon atoms, more preferably 3 to 5 carbon atoms. Specifically, examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, and the like, with an isopropyl group being preferred.

When Ra' ³ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may also be a polycyclic group or a monocyclic group.

As the aliphatic hydrocarbon group which is a monocyclic group, a group in which one hydrogen atom is removed from a monocycloalkane is preferable. As the monocycloalkane, a group having 3 to 6 carbon atoms is preferable, and specific examples thereof include cyclopentane and cyclohexane.

As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable, and as the polycycloalkane, a group having 7 to 12 carbon atoms is preferable, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

When the cyclic hydrocarbon group of Ra' ³ becomes an aromatic hydrocarbon group, the aromatic hydrocarbon group is a hydrocarbon group having at least one aromatic ring.

This aromatic ring is not particularly limited as long as it is a ring-shaped conjugated system having 4n + 2 π electrons, and may be a monocyclic ring or a polycyclic ring. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12.

Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced with heteroatoms. Examples of the heteroatoms in the aromatic heterocycle include oxygen atoms, sulfur atoms, and nitrogen atoms. Specific examples of the aromatic heterocycle include a pyridine ring, a thiophene ring, and the like.

Specific examples of the aromatic hydrocarbon group in Ra' ³ include a group in which one hydrogen atom has been removed from the aromatic hydrocarbon ring or aromatic heterocycle (an aryl group or a heteroaryl group); a group in which one hydrogen atom has been removed from an aromatic compound (for example, biphenyl, fluorene, etc.) containing two or more aromatic rings; a group in which one hydrogen atom of the aromatic hydrocarbon ring or aromatic heterocycle is replaced by an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, or a 2-naphthylethyl group), and the like. The alkylene group bonded to the aromatic hydrocarbon ring or aromatic heterocycle preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

The cyclic hydrocarbon group in Ra' ³ may have a substituent. Examples of this substituent include Ra ^x5 described above.

When Ra' ³ forms a ring by combining with either Ra' ¹ or Ra' ² , the ring group is preferably a 4 to 7-membered ring, and more preferably a 4 to 6-membered ring. Specific examples of the ring group include a tetrahydropyranyl group, a tetrahydrofuranyl group, and the like.

Tertiary alkyl ester type acid-dissociating group:

Among the above polar groups, an acid-labile group protecting a carboxyl group may be, for example, an acid-labile group represented by the following general formula (a1-r-2).

In addition, among the acid-dissociable groups represented by the following formula (a1-r-2), those composed of alkyl groups are sometimes referred to as “tertiary alkyl ester type acid-dissociable groups” for convenience.

[Chemical formula 9]

[In the formula, Ra' ⁴ to Ra' ⁶ are each a hydrocarbon group, and Ra' ⁵ and Ra' ⁶ may be combined with each other to form a ring.]

The hydrocarbon group of Ra' ⁴ may include a linear or branched alkyl group, a linear or cyclic alkenyl group, or a cyclic hydrocarbon group.

The linear or branched alkyl group and cyclic hydrocarbon group (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group, aromatic hydrocarbon group) in Ra' ⁴ can be the same as those in Ra' ³ above.

The chain-shaped or cyclic alkenyl group in Ra' ⁴ is preferably an alkenyl group having 2 to 10 carbon atoms.

As hydrocarbon groups of Ra' ⁵ and Ra' ⁶ , the same ones as those of Ra' ³ can be mentioned.

When Ra' ⁵ and Ra' ⁶ combine with each other to form a ring, a group represented by the following general formula (a1-r2-1), a group represented by the following general formula (a1-r2-2), and a group represented by the following general formula (a1-r2-3) are preferable.

Meanwhile, when Ra' ⁴ to Ra' ⁶ are not bonded to each other and are independent hydrocarbon groups, a group represented by the following general formula (a1-r2-4) can be preferably mentioned.

[Chemical Formula 10]

[In formula (a1-r2-1), Ra' ¹⁰ represents a linear or branched alkyl group having 1 to 12 carbon atoms, which may be partially substituted with a halogen atom or a heteroatom-containing group. Ra' ¹¹ represents a group forming an aliphatic cyclic group together with the carbon atom to which Ra' ¹⁰ is bonded. In formula (a1-r2-2), Ya is a carbon atom. Xa is a group forming a cyclic hydrocarbon group together with Ya. Some or all of the hydrogen atoms contained in this cyclic hydrocarbon group may be substituted. Ra ¹⁰¹ to Ra ¹⁰³ are each independently a hydrogen atom, a monovalent linear saturated hydrocarbon group having 1 to 10 carbon atoms, or a monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms. Some or all of the hydrogen atoms of this chain-type saturated hydrocarbon group and aliphatic cyclic saturated hydrocarbon group may be substituted. Two or more of Ra ¹⁰¹ to Ra ¹⁰³ may be bonded to each other to form a cyclic structure. In formula (a1-r2-3), Yaa is a carbon atom. Xaa is a group forming an aliphatic cyclic group together with Yaa. Ra ¹⁰⁴ is an aromatic hydrocarbon group which may have a substituent. In formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain-type saturated hydrocarbon group having 1 to 10 carbon atoms. Some or all of the hydrogen atoms of this chain-type saturated hydrocarbon group may be substituted. Ra' ¹⁴ is a hydrocarbon group which may have a substituent. * Indicates a bond (hereinafter, the same applies).]

In the above formula (a1-r2-1), Ra' ¹⁰ is a linear or branched alkyl group having 1 to 12 carbon atoms, some of which may be substituted with a halogen atom or a heteroatom-containing group.

In Ra' ¹⁰ , the linear alkyl group has 1 to 12 carbon atoms, preferably 1 to 10 carbon atoms, and particularly preferably 1 to 5 carbon atoms.

As for the branched-chain alkyl group in Ra' ¹⁰ , the same ones as in Ra' ³ can be mentioned.

In Ra' ¹⁰ , some of the alkyl groups may be substituted with halogen atoms or heteroatom-containing groups. For example, some of the hydrogen atoms constituting the alkyl group may be substituted with halogen atoms or heteroatom-containing groups. In addition, some of the carbon atoms (such as a methylene group) constituting the alkyl group may be substituted with heteroatom-containing groups.

Here, the heteroatoms mentioned include oxygen atoms, sulfur atoms, and nitrogen atoms. The heteroatom-containing groups include (-O-), -C(=O)-O-, -OC(=O)-, -C(=O)-, -OC(=O)-O-, -C(=O)-NH-, -NH-, -S-, -S(=O) ₂ -, -S(=O) ₂ -O-, etc.

In formula (a1-r2-1), Ra' ¹¹ (an aliphatic cyclic group formed together with the carbon atom to which Ra' ¹⁰ is bonded) is preferably an aliphatic hydrocarbon group (alicyclic hydrocarbon group) exemplified as a monocyclic group or polycyclic group of Ra' ³ in formula (a1-r-1). Among these, a monocyclic alicyclic hydrocarbon group is preferable, and specifically, a cyclopentyl group and a cyclohexyl group are more preferable.

In formula (a1-r2-2), the cyclic hydrocarbon group formed by Xa together with Ya may include a group in which one or more hydrogen atoms are additionally removed from the cyclic monovalent hydrocarbon group (aliphatic hydrocarbon group) in Ra' ³ in formula (a1-r-1).

The cyclic hydrocarbon group formed by Xa together with Ya may have a substituent. Examples of this substituent include the same substituents as those which the cyclic hydrocarbon group in Ra' ³ may have.

Among the formulas (a1-r2-2), examples of the monovalent chain-shaped saturated hydrocarbon group having 1 to 10 carbon atoms for Ra ¹⁰¹ to Ra ¹⁰³ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a decyl group, and the like.

Examples of the monovalent aliphatic cyclic saturated hydrocarbon group having 3 to 20 carbon atoms in Ra ¹⁰¹ to Ra ¹⁰³ include monocyclic aliphatic saturated hydrocarbon groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group; polycyclic aliphatic saturated hydrocarbon groups such as a bicyclo[2.2.2]octanyl group, a tricyclo[5.2.1.02,6]decanyl group, a tricyclo[3.3.1.13,7]decanyl group, a tetracyclo[6.2.1.13,6.02,7]dodecanyl group, and an adamantyl group.

Among them, from the viewpoint of ease of synthesis, Ra ¹⁰¹ to Ra ¹⁰³ are preferably hydrogen atoms and monovalent chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms, and among them, hydrogen atoms, methyl groups and ethyl groups are more preferable, and hydrogen atoms are particularly preferable.

As a substituent possessed by the chain-shaped saturated hydrocarbon group or the aliphatic cyclic saturated hydrocarbon group represented by Ra ¹⁰¹ to Ra ¹⁰³ above, for example, the same group as Ra ^x5 described above can be mentioned.

Examples of groups containing a carbon-carbon double bond generated when two or more of Ra ¹⁰¹ to Ra ¹⁰³ are bonded to each other to form a ring structure include a cyclopentenyl group, a cyclohexenyl group, a methylcyclopentenyl group, a methylcyclohexenyl group, a cyclopentylideneethenyl group, a cyclohexylideneethenyl group, and the like. Among these, from the viewpoint of ease of synthesis, a cyclopentenyl group, a cyclohexenyl group, and a cyclopentylideneethenyl group are preferable.

Among the formulas (a1-r2-3), the aliphatic cyclic group formed by Xaa together with Yaa is preferably an aliphatic hydrocarbon group exemplified as a monocyclic group or polycyclic group of Ra' ³ in the formula (a1-r-1).

In the formula (a1-r2-3), examples of the aromatic hydrocarbon group for Ra ¹⁰⁴ include a group having 1 or more hydrogen atoms removed from an aromatic hydrocarbon ring having 5 to 30 carbon atoms. Among these, Ra ¹⁰⁴ is preferably a group having 1 or more hydrogen atoms removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group having 1 or more hydrogen atoms removed from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group having 1 or more hydrogen atoms removed from benzene, naphthalene or anthracene, particularly preferably a group having 1 or more hydrogen atoms removed from benzene or naphthalene, and most preferably a group having 1 or more hydrogen atoms removed from benzene.

Substituents that Ra ¹⁰⁴ in the formula (a1-r2-3) may have include, for example, a methyl group, an ethyl group, a propyl group, a hydroxyl group, a carboxyl group, a halogen atom, an alkoxy group (such as a methoxy group, an ethoxy group, a propoxy group, or a butoxy group), an alkyloxycarbonyl group, and the like.

In the formula (a1-r2-4), Ra' ¹² and Ra' ¹³ are each independently a monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms. Examples of the monovalent chain-like saturated hydrocarbon group having 1 to 10 carbon atoms in Ra' ¹² and Ra' ¹³ include the same chain-like saturated hydrocarbon groups having 1 to 10 carbon atoms as those in Ra ¹⁰¹ to Ra ^103. Some or all of the hydrogen atoms in this chain-like saturated hydrocarbon group may be substituted.

Among Ra' ¹² and Ra' ¹³ , an alkyl group having 1 to 5 carbon atoms is preferable, an alkyl group having 1 to 5 carbon atoms is more preferable, a methyl group or an ethyl group is further preferable, and a methyl group is particularly preferable.

When the chain-shaped saturated hydrocarbon groups represented by the above Ra' ¹² and Ra' ¹³ are substituted, the substituents include, for example, the same groups as Ra ^x5 described above.

In the formula (a1-r2-4), Ra' ¹⁴ is a hydrocarbon group which may have a substituent. The hydrocarbon group for Ra' ¹⁴ may include a linear or branched alkyl group, or a cyclic hydrocarbon group.

The linear alkyl group in Ra' ¹⁴ preferably has 1 to 5 carbon atoms, more preferably 1 to 4, and even more preferably 1 or 2. Specifically, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group, and the like can be mentioned. Among these, a methyl group, an ethyl group, or an n-butyl group is preferable, and a methyl group or an ethyl group is more preferable.

The branched alkyl group in Ra' ¹⁴ preferably has 3 to 10 carbon atoms, more preferably 3 to 5. Specifically, examples thereof include an isopropyl group, an isobutyl group, a tert-butyl group, an isopentyl group, a neopentyl group, a 1,1-diethylpropyl group, a 2,2-dimethylbutyl group, and the like, with an isopropyl group being preferable.

When Ra' ¹⁴ is a cyclic hydrocarbon group, the hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group, and may also be a polycyclic group or a monocyclic group.

As the aliphatic hydrocarbon group which is a monocyclic group, a group in which one hydrogen atom is removed from a monocycloalkane is preferable. As the monocycloalkane, a group having 3 to 6 carbon atoms is preferable, and specific examples thereof include cyclopentane and cyclohexane.

As the aliphatic hydrocarbon group which is a polycyclic group, a group obtained by removing one hydrogen atom from a polycycloalkane is preferable, and as the polycycloalkane, a group having 7 to 12 carbon atoms is preferable, and specific examples thereof include adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane.

As the aromatic hydrocarbon group for Ra' ¹⁴ , the same ones as the aromatic hydrocarbon group for Ra ¹⁰⁴ can be exemplified. Among these, Ra' ¹⁴ is preferably a group having 1 or more hydrogen atoms removed from an aromatic hydrocarbon ring having 6 to 15 carbon atoms, more preferably a group having 1 or more hydrogen atoms removed from benzene, naphthalene, anthracene or phenanthrene, still more preferably a group having 1 or more hydrogen atoms removed from benzene, naphthalene or anthracene, particularly preferably a group having 1 or more hydrogen atoms removed from naphthalene or anthracene, and most preferably a group having 1 or more hydrogen atoms removed from naphthalene.

The substituents that Ra' ¹⁴ may have are the same as the substituents that Ra ¹⁰⁴ may have.

When Ra' ¹⁴ in formula (a1-r2-4) is a naphthyl group, the position bonded to the tertiary carbon atom in the formula (a1-r2-4) may be either the 1st position or the 2nd position of the naphthyl group.

When Ra' ¹⁴ in formula (a1-r2-4) is an anthryl group, the position bonded to the tertiary carbon atom in the formula (a1-r2-4) may be any of the 1st, 2nd, or 9th positions of the anthryl group.

Specific examples of groups represented by the above formula (a1-r2-1) are given below.

[Chemical Formula 11]

[Chemical Formula 12]

[Chemical Formula 13]

Specific examples of groups represented by the above formula (a1-r2-2) are given below.

[Chemical Formula 14]

[Chemical Formula 15]

[Chemical Formula 16]

Specific examples of groups represented by the above formula (a1-r2-3) are given below.

[Chemical Formula 17]

Specific examples of groups represented by the above formula (a1-r2-4) are given below.

[Chemical Formula 18]

Tertiary alkyloxycarbonyl acid dissociation group:

As an acid-labile group protecting a hydroxyl group among the above polar groups, an acid-labile group represented by the following general formula (a1-r-3) (hereinafter, for convenience, sometimes referred to as a “tertiary alkyloxycarbonyl acid-labile group”) can be mentioned.

[Chemical Formula 19]

[In the formula, Ra' ⁷ to Ra' ⁹ are each an alkyl group.]

In formula (a1-r-3), Ra' ⁷ to Ra' ⁹ are each preferably an alkyl group having 1 to 5 carbon atoms, and more preferably an alkyl group having 1 to 3 carbon atoms.

In addition, the total number of carbon atoms of each alkyl group is preferably 3 to 7, more preferably 3 to 5, and most preferably 3 to 4.

As the structural unit (a1), examples thereof include a structural unit derived from an acrylic acid ester in which a hydrogen atom bonded to a carbon atom at the α-position may be substituted with a substituent, a structural unit derived from acrylamide, a structural unit derived from hydroxystyrene or a hydroxystyrene derivative in which at least a part of the hydrogen atoms in a hydroxyl group of the structural unit are protected by a substituent containing the acid-decomposable group, a structural unit derived from vinylbenzoic acid or a vinylbenzoic acid derivative in which at least a part of the hydrogen atoms in -C(=O)-OH of the structural unit are protected by a substituent containing the acid-decomposable group, and the like.

Second-class alkyl ester type acid-dissociating group:

Among the above polar groups, an acid-labile group protecting a carboxyl group may be, for example, an acid-labile group represented by the following general formula (a1-r-4).

[Chemical formula 20]

[In the formula, Ra' ¹⁰ is a hydrocarbon group. Ra' ^11a and Ra' ^11b are each independently a hydrogen atom, a halogen atom or an alkyl group. Ra' ¹² is a hydrogen atom or a hydrocarbon group. Ra' ¹⁰ and Ra' ^11a or Ra' ^11b may be combined with each other to form a ring. Ra' ^11a or Ra' ^11b and Ra' ¹² may be combined with each other to form a ring.]

Among the hydrocarbon groups in Ra' ¹⁰ and Ra' ¹² , the same groups as Ra' ³ can be mentioned.

Among the compounds, the alkyl groups in Ra' ^11a and Ra' ^11b include the same groups as the alkyl groups in Ra' ¹ .

In the formula, the hydrocarbon groups in Ra' ¹⁰ and Ra' ¹² , and the alkyl groups in Ra' ^11a and Ra' ^11b may have a substituent. Examples of the substituent include Ra ^x5 described above.

Ra' ¹⁰ and Ra' ^11a or Ra' ^11b may be combined with each other to form a ring. The ring may be a polycyclic ring, a monocyclic ring, a cyclic ring, or an aromatic ring.

The ring and the directional ring may contain a hetero atom.

Among the above, as a ring formed by combining Ra' ¹⁰ and Ra' ^11a or Ra' ^11b , a monocycloalkene, a ring in which some of the carbon atoms of the monocycloalkene are replaced with heteroatoms (oxygen atoms, sulfur atoms, etc.), and monocycloalkadiene are preferable, a cycloalkene having 3 to 6 carbon atoms is preferable, and cyclopentene or cyclohexene is preferable.

The ring formed by combining Ra' ¹⁰ and Ra' ^11a or Ra' ^11b may be a condensed ring. Specific examples of the condensed ring include indane and the like.

The ring formed by combining Ra' ¹⁰ and Ra' ^11a or Ra' ^11b may have a substituent. Examples of the substituent include Ra ^x5 described above.

Ra' ^11a or Ra' ^11b and Ra' ¹² may combine with each other to form a ring, and as the ring, an example thereof may be the same as the ring formed by Ra' ¹⁰ and Ra' ^11a or Ra' ^11b combining with each other.

Specific examples of groups represented by the above formula (a1-r-4) are given below.

[Chemical Formula 21]

Specific examples of the structural unit (a1) are shown below. In each formula below, R ^α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[Chemical Formula 22]

[Chemical Formula 23]

[Chemical Formula 24]

[Chemical Formula 25]

[Chemical Formula 26]

[Chemical Formula 27]

[Chemical formula 28]

[Chemical Formula 29]

(A1) The composition unit (a1) of the component may be one type or two or more types.

(A1) The proportion of the structural unit (a1) among the components is preferably 50 mol% or less, and more preferably 0 to 30 mol%, with respect to the total (100 mol%) of the structural units constituting the (A1) component.

About the composition unit (a10):

The constituent unit (a10) is a constituent unit represented by the following general formula (a10-1).

However, the components corresponding to the above-described component unit (a01) are excluded.

[Chemical formula 30]

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ^x1 is a single bond or a divalent linking group. Wa ^x1 is an aromatic hydrocarbon group which may have a substituent. n _ax1 is an integer greater than or equal to 1.]

In the above formula (a10-1), R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms.

As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of industrial availability, a hydrogen atom, a methyl group or a trifluoromethyl group is more preferable, a hydrogen atom or a methyl group is even more preferable, and a hydrogen atom is particularly preferable.

In the above formula (a10-1), Ya ^x1 is a single bond or a divalent linking group.

In the above chemical formula, the divalent linking group in Ya ^x1 is not particularly limited, but preferable examples thereof include a divalent hydrocarbon group that may have a substituent, a divalent linking group containing a hetero atom, and the like.

For Ya ^x1 , it is preferable that it is a single bond, an ester bond [-C(=O)-O-, -OC(=O)-], an ether bond (-O-), a linear or branched alkylene group, or a combination of these, and a single bond, an ester bond [-C(=O)-O-, -OC(=O)-] is more preferable.

In the above formula (a10-1), Wa ^x1 is an aromatic hydrocarbon group which may have a substituent.

As an aromatic hydrocarbon group in Wa ^x1 , a group in which (n _ax1 + 1) hydrogen atoms are removed from an aromatic ring which may have a substituent can be mentioned. The aromatic ring here is not particularly limited as long as it is a cyclic conjugated system having 4n + 2 π electrons. The number of carbon atoms in the aromatic ring is preferably 5 to 30, more preferably 5 to 20, still more preferably 6 to 15, and particularly preferably 6 to 12. Specific examples of the aromatic ring include aromatic hydrocarbon rings such as benzene, naphthalene, anthracene, and phenanthrene; and aromatic heterocycles in which some of the carbon atoms constituting the aromatic hydrocarbon ring are replaced with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom, and the like. As aromatic heterocyclic rings, specific examples include a pyridine ring and a thiophene ring.

In addition, as an aromatic hydrocarbon group in Wa ^x1 , a group in which (n _ax1 + 1) hydrogen atoms are removed from an aromatic compound (e.g., biphenyl, fluorene, etc.) containing an aromatic ring that may have two or more substituents can also be mentioned.

Among the above, as Wa ^x1 , a group in which (n _ax1 + 1) hydrogen atoms are removed from benzene, naphthalene, anthracene or biphenyl is preferable, a group in which (n _ax1 + 1) hydrogen atoms are removed from benzene or naphthalene is more preferable, and a group in which (n _ax1 + 1) hydrogen atoms are removed from benzene is still more preferable.

The aromatic hydrocarbon group in Wa ^x1 may or may not have a substituent. Examples of the substituent include an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, and the like. Examples of the alkyl group, an alkoxy group, a halogen atom, and a halogenated alkyl group as the substituent include the same as those exemplified as the substituent for the cyclic aliphatic hydrocarbon group in Ya ^x1 . The substituent is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, more preferably a linear or branched alkyl group having 1 to 3 carbon atoms, still more preferably an ethyl group or a methyl group, and particularly preferably a methyl group. The aromatic hydrocarbon group in Wa ^x1 preferably does not have a substituent.

In the above formula (a10-1), n _ax1 is an integer greater than or equal to 1, preferably an integer of 1 to 10, more preferably an integer of 1 to 5, still more preferably 1, 2 or 3, and particularly preferably 1 or 2.

Below, a specific example of the constituent unit (a10) represented by the above formula (a10-1) is shown.

In each of the formulas below, R ^α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[Chemical Formula 31]

[Chemical formula 32]

[Chemical formula 33]

(A1) The composition unit (a10) of the component may be one type or two or more types.

When the (A1) component has a structural unit (a10), the proportion of the structural unit (a10) in the (A1) component is preferably 20 to 80 mol%, more preferably 30 to 70 mol%, and still more preferably 30 to 60 mol%, with respect to the total (100 mol%) of the entire structural units constituting the (A1) component.

By setting the ratio of the constituent unit (a10) above the lower limit, it becomes easier to increase the sensitivity. On the other hand, by setting it below the upper limit, it becomes easier to maintain a balance with other constituent units.

About the composition unit (a2):

(A1) The component may additionally have a structural unit (a2) including a lactone-containing cyclic group (except for those corresponding to structural units (a01) and (a1)).

The lactone-containing ring group of the structural unit (a2) is effective in increasing the adhesion of the resist film to the substrate when the (A1) component is used to form the resist film. In addition, by having the structural unit (a2), lithography characteristics, etc. are improved due to effects such as appropriately adjusting the acid diffusion length, increasing the adhesion of the resist film to the substrate, or appropriately adjusting the solubility during development.

A "lactone-containing cyclic group" refers to a cyclic group containing a ring (lactone ring) containing -O-C(=O)- in its ring skeleton. The lactone ring is counted as the first ring, and if it is only a lactone ring, it is called a monocyclic group, and if it additionally has another ring structure, it is called a polycyclic group regardless of the structure. The lactone-containing cyclic group may be a monocyclic group or a polycyclic group.

As for the lactone-containing cyclic group in the constituent unit (a2), any group can be used without particular limitation. Specifically, groups represented by the following general formulae (a2-r-1) to (a2-r-7) can be mentioned.

[Chemical Formula 34]

[In the formula, Ra' ²¹ is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group; A" is an alkylene group having 1 to 5 carbon atoms which may include an oxygen atom (-O-) or a sulfur atom (-S-), an oxygen atom, or a sulfur atom, n' is an integer of 0 to 2, and m' is 0 or 1. * represents a bond (hereinafter, the same applies).]

Among the above general formulas (a2-r-1) to (a2-r-7), the alkyl group for Ra' ²¹ is preferably an alkyl group having 1 to 6 carbon atoms. The alkyl group is preferably linear or branched. Specifically, examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, a hexyl group, and the like. Among these, a methyl group or an ethyl group is preferable, and a methyl group is particularly preferable.

As the alkoxy group in Ra' ²¹ , an alkoxy group having 1 to 6 carbon atoms is preferable. The alkoxy group is preferably linear or branched. Specifically, a group in which an alkyl group as exemplified as the alkyl group in Ra' ²¹ is linked to an oxygen atom (-O-) can be exemplified.

As the halogen atom in Ra' ²¹ , a fluorine atom is preferable.

As the halogenated alkyl group in Ra' ²¹ , a group in which some or all of the hydrogen atoms of the alkyl group in Ra' ²¹ are replaced with the halogen atoms can be exemplified. As the halogenated alkyl group, a fluorinated alkyl group is preferable, and a perfluoroalkyl group is particularly preferable.

In -COOR", -OC(=O)R" in Ra' ²¹ , R" is a hydrogen atom, an alkyl group, or a lactone-containing cyclic group.

The alkyl group in "R" may be any of a linear, branched, or cyclic type, and the number of carbon atoms is preferably 1 to 15.

When "R" is a linear or branched alkyl group, it is preferably one having 1 to 10 carbon atoms, more preferably one having 1 to 5 carbon atoms, and particularly preferably a methyl group or an ethyl group.

When "R" is a cyclic alkyl group, it is preferably one having 3 to 15 carbon atoms, more preferably one having 4 to 12 carbon atoms, and most preferably one having 5 to 10 carbon atoms. Specifically, examples thereof include a group having one or more hydrogen atoms removed from a monocycloalkane, which may or may not be substituted with a fluorine atom or a fluorinated alkyl group; a group having one or more hydrogen atoms removed from a polycycloalkane such as a bicycloalkane, a tricycloalkane, or a tetracycloalkane; and more specifically, a group having one or more hydrogen atoms removed from a monocycloalkane such as cyclopentane or cyclohexane; a group having one or more hydrogen atoms removed from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane.

As the lactone-containing cyclic group in "R", the same groups as those represented by the general formulae (a2-r-1) to (a2-r-7) can be exemplified.

As the hydroxyalkyl group in Ra' ²¹ , a group having 1 to 6 carbon atoms is preferable, and specifically, a group in which at least one of the hydrogen atoms of the alkyl group in Ra' ²¹ is replaced with a hydroxyl group can be mentioned.

Among the above, it is preferable that Ra' ²¹ is independently a hydrogen atom or a cyano group.

Among the above general formulas (a2-r-2), (a2-r-3), and (a2-r-5), the alkylene group having 1 to 5 carbon atoms in A" is preferably a linear or branched alkylene group, and examples thereof include a methylene group, an ethylene group, an n-propylene group, and an isopropylene group. When the alkylene group contains an oxygen atom or a sulfur atom, specific examples thereof include a group in which -O- or -S- is interposed between the terminals or carbon atoms of the alkylene group, and examples thereof include -O-CH ₂ -, -CH ₂ -O-CH ₂ -, -S-CH ₂ -, -CH ₂ -S-CH ₂ -, and the like. As A", an alkylene group having 1 to 5 carbon atoms or -O- is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is most preferable.

Below are specific examples of groups represented by the general formulas (a2-r-1) to (a2-r-7).

[Chemical Formula 35]

[Chemical formula 36]

As the structural unit (a2), among them, a structural unit derived from an acrylic acid ester in which the hydrogen atom bonded to the carbon atom at the α position may be substituted with a substituent is preferable.

It is preferable that these constituent units (a2) be constituent units represented by the following general formula (a2-1).

[Chemical Formula 37]

[In the formula, R is a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms. Ya ²¹ is a single bond or a divalent linking group. La ²¹ is -O-, -COO-, -CON(R')-, -OCO-, -CONHCO-, or -CONHCS-, and R' represents a hydrogen atom or a methyl group. However, when La ²¹ is -O-, Ya ²¹ does not become -CO-. Ra ²¹ is a lactone-containing cyclic group.]

In the above formula (a2-1), R is the same as above. As R, a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a fluorinated alkyl group having 1 to 5 carbon atoms is preferable, and from the viewpoint of industrial availability, a hydrogen atom or a methyl group is particularly preferable.

In the above formula (a2-1), the divalent linking group in Ya ²¹ is not particularly limited, but preferably includes a divalent hydrocarbon group which may have a substituent, a divalent linking group containing a hetero atom, and the like.

For Ya ²¹ , it is preferable that it be a single bond, an ester bond [-C(=O)-O-], an ether bond (-O-), a linear or branched alkylene group, or a combination of these.

In the above formula (a2-1), it is preferable that Ya ²¹ is a single bond and La ²¹ is -COO- or -OCO-.

In the above formula (a2-1), Ra ²¹ is a lactone-containing cyclic group.

As the lactone-containing cyclic group in Ra ²¹ , groups represented by the general formulae (a2-r-1) to (a2-r-7) described above can be preferably mentioned.

Among these, a group represented by the general formula (a2-r-1), (a2-r-2), or (a2-r-6) is preferable, and a group represented by the general formula (a2-r-1) or (a2-r-2) is more preferable. Specifically, any group represented by the chemical formulas (r-lc-1-1) to (r-lc-1-7), (r-lc-2-1) to (r-lc-2-18), (r-lc-6-1) is preferable, and any group represented by the chemical formulas (r-lc-1-1), (r-lc-2-1), or (r-lc-2-7) is more preferable.

(A1) The composition unit (a2) of the component may be one type or two or more types.

When the (A1) component has a structural unit (a2), the proportion of the structural unit (a2) is preferably 5 to 80 mol%, more preferably 5 to 70 mol%, and even more preferably 5 to 60 mol%, with respect to the total (100 mol%) of all structural units constituting the (A1) component.

When the ratio of the constituent unit (a2) is set to a preferable lower limit or higher, the effect of containing the constituent unit (a2) is sufficiently obtained due to the above-mentioned effect, and when it is set to a value lower than the upper limit, a balance with other constituent units can be achieved, and various lithographic characteristics become good.

About the composition unit (a8):

The constituent unit (a8) is a constituent unit derived from a compound represented by the following general formula (a8-1).

However, those corresponding to the composition unit (a0) are excluded.

[Chemical formula 38]

[In the formula, W ² is a polymerizable group-containing group. Ya ^x2 is a single bond or a connecting group having (n _ax2 + 1). Ya ^x2 and W ² may form a condensed ring. R ¹ is a fluorinated alkyl group having 1 to 12 carbon atoms. R ² is an organic group having 1 to 12 carbon atoms which may have a fluorine atom or a hydrogen atom. R ² and Ya ^x2 may be bonded to each other to form a ring structure. n _ax2 is an integer of 1 to 3.]

The “polymerizable group” in the polymerizable group-containing group of ^W2 is a group that enables a compound having a polymerizable group to polymerize by radical polymerization or the like, and refers to a group that includes multiple bonds between carbon atoms, such as an ethylenic double bond, for example.

The polymerizable group-containing group may be a group composed of only a polymerizable group, or a group composed of a polymerizable group and another group other than the polymerizable group. Examples of groups other than the polymerizable group include a divalent hydrocarbon group that may have a substituent, a divalent linking group containing a hetero atom, etc.

As a polymerizable group-containing group, a group represented by the chemical formula: C(R ^X11 )(R ^X12 )=C(R ^X13 )-Ya ^x0- can be preferably exemplified.

In this chemical formula, R ^X11 , R ^X12 , and R ^X13 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Ya ^x0 is a single bond or a divalent linking group.

The condensed ring formed by Ya ^x2 and W ² may include a condensed ring formed by Ya ^x2 and a polymerizable group at the W ² site, and a condensed ring formed by Ya ^x2 and a group other than the polymerizable group at the W ² site.

The condensed ring formed by Ya ^x2 and W ² may have a substituent.

Below, a specific example of the constituent unit (a8) is shown.

In the formula below, R ^α represents a hydrogen atom, a methyl group, or a trifluoromethyl group.

[Chemical Formula 39]

Among the above examples, the structural unit (a8) is preferably at least one selected from the group consisting of structural units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-06), (a8-1-08), (a8-1-09), and (a8-1-10), and more preferably at least one selected from the group consisting of structural units represented by chemical formulas (a8-1-01) to (a8-1-04), (a8-1-09).

(A1) The composition unit (a8) of the component may be one type or two or more types.

The ratio of the constituent unit (a8) in the (A1) component is preferably 50 mol% or less, and more preferably 0 to 30 mol%, with respect to the total (100 mol%) of all constituent units constituting the (A1) component.

The (A1) component contained in the resist composition may be used alone or in combination of two or more types.

In the resist composition of the present embodiment, the component (A1) may be a polymer compound having a repeating structure of the structural unit (a01).

(A1) As the component, among the above, a polymer compound including a repeating structure of the structural unit (a01) and the structural unit (a10) can be preferably mentioned.

More specifically, as the component (A1), a polymer compound comprising a repeating structure of a structural unit (a01) and a structural unit (a10); a polymer compound comprising a repeating structure of a structural unit (a01) and a structural unit (a2); and a polymer compound comprising a repeating structure of a structural unit (a01), a structural unit (a10), and a structural unit (a2) are preferably mentioned.

In a polymer compound having a repeating structure of a structural unit (a01) and a structural unit (a10), the proportion of the structural unit (a01) is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, with respect to the total (100 mol%) of all structural units constituting the polymer compound.

In addition, the ratio of the structural unit (a10) in the polymer compound is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, with respect to the total (100 mol%) of all structural units constituting the polymer compound.

In a polymer compound having a repeating structure of a structural unit (a01) and a structural unit (a2), the proportion of the structural unit (a01) is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, with respect to the total (100 mol%) of all structural units constituting the polymer compound.

In addition, the proportion of the structural unit (a2) in the polymer compound is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, relative to the total (100 mol%) of all structural units constituting the polymer compound.

In a polymer compound having a repeating structure of a structural unit (a01), a structural unit (a10), and a structural unit (a2), the proportion of the structural unit (a01) is preferably 10 to 90 mol%, more preferably 20 to 80 mol%, still more preferably 30 to 70 mol%, and particularly preferably 40 to 60 mol%, with respect to the total (100 mol%) of all structural units constituting the polymer compound.

In addition, the ratio of the structural unit (a10) in the polymer compound is preferably 5 to 80 mol%, more preferably 10 to 70 mol%, still more preferably 20 to 60 mol%, and particularly preferably 30 to 50 mol%, relative to the total (100 mol%) of all structural units constituting the polymer compound.

In addition, the proportion of the structural unit (a2) in the polymer compound is preferably 1 to 30 mol%, more preferably 3 to 20 mol%, still more preferably 5 to 20 mol%, and particularly preferably 5 to 15 mol%, relative to the total (100 mol%) of all structural units constituting the polymer compound.

These (A1) components can be produced by dissolving the monomers that induce each constituent unit in a polymerization solvent and adding a radical polymerization initiator, such as azobisisobutyronitrile (AIBN), dimethyl azobisisobutyrate (e.g., V-601), to polymerize.

Alternatively, the (A1) component can be produced by dissolving a monomer that induces the structural unit (a01) and, if necessary, a monomer that induces a structural unit other than the structural unit (a01) (for example, the structural unit (a10)), in a polymerization solvent, adding a radical polymerization initiator as described above to polymerize the monomer, and then performing a deprotection reaction.

In addition, during polymerization, a chain transfer agent such as HS-CH ₂ -CH ₂ -CH ₂ -C(CF ₃ ) ₂ -OH may be used in combination to introduce a -C(CF ₃ ) ₂ -OH group at the terminal. In this way, a copolymer having a hydroxyalkyl group in which some of the hydrogen atoms of the alkyl group are replaced with fluorine atoms is introduced is effective in reducing development defects or LER (line edge roughness: uneven unevenness of the line side wall).

(A1) The weight average molecular weight (Mw) of the component (based on polystyrene conversion by gel permeation chromatography (GPC)) is not particularly limited, and is preferably 1,000 to 50,000, more preferably 2,000 to 30,000, and still more preferably 3,000 to 20,000.

(A1) If the Mw of the component is equal to or lower than the preferred upper limit of this range, the composition has sufficient solubility in a resist solvent for use as a resist, and if it is equal to or higher than the preferred lower limit of this range, the dry etching resistance and the resist pattern cross-sectional shape are good.

(A1) The dispersion ratio (Mw/Mn) of the component is not particularly limited, and is preferably 1.0 to 4.0, more preferably 1.0 to 3.0, and particularly preferably 1.0 to 2.0. In addition, Mn represents the number average molecular weight.

· (A2) About the ingredients

The resist composition of the present embodiment may use, as component (A), a base component (hereinafter referred to as “component (A2)”) whose solubility in a developer changes by the action of an acid, which does not correspond to component (A1).

(A2) The component is not particularly limited, and may be arbitrarily selected and used from a number of components known in the art as base components for chemically amplified resist compositions.

(A2) The component may be used alone as one type of high molecular weight compound or low molecular weight compound, or may be used in combination of two or more types.

(A) The proportion of component (A1) among the components is preferably 25 mass% or more, more preferably 50 mass% or more, still more preferably 75 mass% or more, and may be 100 mass%, with respect to the total mass of component (A). When the proportion is 25 mass% or more, a resist pattern excellent in various lithographic characteristics such as high sensitivity, resolution, and roughness improvement is easily formed.

In the resist composition of the present embodiment, the content of component (A) may be adjusted depending on the thickness of the resist film to be formed, etc.

＜Other ingredients＞

The resist composition of the present embodiment may additionally contain other components in addition to the above-described component (A). Examples of the other components include component (B), component (D), component (E), component (F), and component (S) shown below.

≪Acid generating agent component (B)≫

The resist composition of the present embodiment preferably further contains an acid generator component (B) that generates acid upon exposure.

(B) As a component, any one that has been proposed so far as an acid generator for a chemically amplified resist composition can be used without particular limitation.

Examples of such acid generators include onium salt-based acid generators such as iodonium salts or sulfonium salts; oxime sulfonate-based acid generators; diazomethane-based acid generators such as bisalkyl or bisarylsulfonyldiazomethanes and poly(bissulfonyl)diazomethanes; nitrobenzylsulfonate-based acid generators, iminosulfonate-based acid generators, disulfone-based acid generators, and the like.

Examples of the onium salt-based acid generator include a compound represented by the following general formula (b-1) (hereinafter also referred to as the “(b-1) component”), a compound represented by the following general formula (b-2) (hereinafter also referred to as the “(b-2) component”), or a compound represented by the following general formula (b-3) (hereinafter also referred to as the “(b-3) component”).

[Chemical formula 40]

[Wherein, R ¹⁰¹ and R ¹⁰⁴ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain-like alkyl group which may have a substituent, or a chain-like alkenyl group which may have a substituent. R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring structure. R ¹⁰² is a fluorinated alkyl group having 1 to 5 carbon atoms or a fluorine atom. Y ¹⁰¹ is a divalent linking group containing an oxygen atom or a single bond. V ¹⁰¹ to V ¹⁰³ are each independently a single bond, an alkylene group or a fluorinated alkylene group. L ¹⁰¹ to L ¹⁰² are each independently a single bond or an oxygen atom. L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -. m is an integer greater than or equal to 1, and M' ^m＋ is an onium cation of valence m.]

{Anion Department}

· Anion in (b-1) component

In formula (b-1), R ¹⁰¹ is a cyclic group which may have a substituent, a chain-shaped alkyl group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent.

Cyclic groups that may have substituents:

The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. In addition, the aliphatic hydrocarbon group may be saturated or unsaturated, and usually, it is preferable that it is saturated.

The aromatic hydrocarbon group in R ¹⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30, still more preferably 5 to 20, particularly preferably 6 to 15, and most preferably 6 to 10. However, the number of carbon atoms does not include the number of carbon atoms in the substituent.

Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group in R ¹⁰¹ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocycle in which some of the carbon atoms constituting these aromatic rings are replaced with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom, and the like.

Specific examples of the aromatic hydrocarbon group for R ¹⁰¹ include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been replaced with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.). The number of carbon atoms in the alkylene group (the alkyl chain in the arylalkyl group) is preferably 1 to 4, more preferably 1 to 2, and particularly preferably 1.

The cyclic aliphatic hydrocarbon group in R ¹⁰¹ may be an aliphatic hydrocarbon group containing a ring in its structure.

Among these structures, examples of aliphatic hydrocarbon groups containing a ring include an alicyclic hydrocarbon group (a group in which one hydrogen atom is removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.

The above-mentioned alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms.

The above-mentioned alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. As the monocycloalkane, a group having 3 to 6 carbon atoms is preferable, and specific examples thereof include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane is preferably a group having 7 to 30 carbon atoms. Among these, examples of the polycycloalkane include polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; A polycycloalkane having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton, is more preferable.

Among these, as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ , a group having at least one hydrogen atom removed from a monocycloalkane or a polycycloalkane is preferable, a group having one hydrogen atom removed from a polycycloalkane is more preferable, an adamantyl group or a norbornyl group is further preferable, and an adamantyl group is particularly preferable.

The linear aliphatic hydrocarbon group which may be bonded to an alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6, still more preferably 1 to 4, and most preferably 1 to 3. As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specific examples thereof include a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [-(CH ₂ ) ₃ -], a tetramethylene group [-(CH ₂ ) ₄ -], and a pentamethylene group [-(CH ₂ ) ₅ -].

The branched aliphatic hydrocarbon group which may be bonded to an alicyclic hydrocarbon group preferably has 2 to 10 carbon atoms, more preferably 3 to 6, still more preferably 3 or 4, and most preferably 3. As the branched aliphatic hydrocarbon group, a branched alkylene group is preferable, and specifically, alkylmethylene groups such as -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ -; Examples thereof include alkylethylene groups such as -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ CH ₃ ) ₂ -CH ₂ -; alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; alkyltetramethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, and the like; and alkylalkylene groups. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

In addition, the cyclic hydrocarbon group for R ¹⁰¹ may contain a heteroatom such as a heterocyclic ring. Specifically, examples thereof include lactone-containing cyclic groups represented by each of the general formulae (a2-r-1) to (a2-r-7), -SO ₂ - containing cyclic groups represented by each of the following general formulae (b5-r-1) to (b5-r-4), and other heterocyclic groups represented by each of the following chemical formulae (r-hr-1) to (r-hr-16). In the formulas, * represents a bond bonding to Y ¹⁰¹ in formula (b-1).

[Chemical Formula 41]

[In the formula, Rb' ⁵¹ is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group, or a cyano group; R" is a hydrogen atom, an alkyl group, a lactone-containing cyclic group, or a -SO ₂ -containing cyclic group; B" is an alkylene group having 1 to 5 carbon atoms which may include an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom, and n' is an integer of 0 to 2. * represents a bond.]

In the above general formulas (b5-r-1) to (b5-r-2), B" is an alkylene group having 1 to 5 carbon atoms which may include an oxygen atom or a sulfur atom, an oxygen atom, or a sulfur atom.

As for "B", an alkylene group having 1 to 5 carbon atoms or -O- is preferable, an alkylene group having 1 to 5 carbon atoms is more preferable, and a methylene group is even more preferable.

In the above general formulas (b5-r-1) to (b5-r-4), Rb' ⁵¹ is each independently a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, -COOR", -OC(=O)R", a hydroxyalkyl group or a cyano group, and among these, those that are each independently a hydrogen atom or a cyano group are preferable.

Below are specific examples of groups represented by the general formulas (b5-r-1) to (b5-r-4). “Ac” in the formulas represents an acetyl group.

[Chemical formula 42]

[Chemical Formula 43]

[Chemical Formula 44]

[Chemical Formula 45]

Substituents in the cyclic group of R ¹⁰¹ include, for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, and the like.

As an alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable.

As an alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are most preferable.

Halogen atoms as a substituent include fluorine atoms, chlorine atoms, bromine atoms, iodine atoms, etc., and fluorine atoms are preferred.

As a halogenated alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc., in which some or all of the hydrogen atoms are replaced with the halogen atoms, can be exemplified.

The carbonyl group as a substituent is a group that substitutes a methylene group (-CH ₂ -) that constitutes a cyclic hydrocarbon group.

The cyclic hydrocarbon group in R ¹⁰¹ may be a condensed ring group including a condensed ring in which an aliphatic hydrocarbon ring and an aromatic ring are condensed. As the condensed ring, for example, a polycycloalkane having a polycyclic skeleton of a bridged ring system and one or more aromatic rings are condensed can be mentioned. Specific examples of the bridged ring system polycycloalkane include bicycloalkanes such as bicyclo[2.2.1]heptane (norbornane) and bicyclo[2.2.2]octane. As the condensed ring group, a group including a condensed ring in which two or three aromatic rings are condensed to a bicycloalkane is preferable, and a group including a condensed ring in which two or three aromatic rings are condensed to bicyclo[2.2.2]octane is more preferable. Specific examples of the condensed ring group in R ¹⁰¹ include those represented by the following formulae (r-br-1) to (r-br-2). In the formulae, * represents a bond bonding to Y ¹⁰¹ in formula (b-1).

[Chemical Formula 46]

Substituents that the condensed ring group in R ¹⁰¹ may have include, for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, etc.

As the substituents of the above condensed ring group, the alkyl group, the alkoxy group, the halogen atom, and the halogenated alkyl group may be the same as those exemplified as the substituents of the ring group in R ¹⁰¹ .

As an aromatic hydrocarbon group as a substituent of the above-mentioned condensed ring group, examples thereof include a group in which one hydrogen atom is removed from an aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one of the hydrogen atoms of the aromatic ring is replaced with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.), a heterocyclic group represented by each of the above-mentioned formulae (r-hr-1) to (r-hr-6), etc.

As the alicyclic hydrocarbon group as a substituent of the above-mentioned condensed ring group, examples thereof include a group obtained by removing one hydrogen atom from a monocycloalkane such as cyclopentane or cyclohexane; a group obtained by removing one hydrogen atom from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane or tetracyclododecane; a lactone-containing cyclic group represented by each of the above general formulae (a2-r-1) to (a2-r-7); a -SO ₂ - containing cyclic group represented by each of the above general formulae (b5-r-1) to (b5-r-4); and a heterocyclic group represented by each of the above formulae (r-hr-7) to (r-hr-16).

Chain-shaped alkyl group which may have a substituent:

The chain-type alkyl group of R ¹⁰¹ may be either linear or branched.

As for the linear alkyl group, those having 1 to 20 carbon atoms are preferable, those having 1 to 15 carbon atoms are more preferable, and those having 1 to 10 are most preferable.

As the branched-chain alkyl group, those having 3 to 20 carbon atoms are preferable, those having 3 to 15 carbon atoms are more preferable, and those having 3 to 10 are most preferable. Specifically, examples thereof include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

Chain-shaped alkenyl group which may have a substituent:

The chain-shaped alkenyl group of R ¹⁰¹ may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5, still more preferably 2 to 4, and particularly preferably 3. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), a butynyl group, and the like. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.

Among the chain-shaped alkenyl groups, a linear alkenyl group is preferable, a vinyl group or a propenyl group is more preferable, and a vinyl group is particularly preferable.

Substituents in the chain-shaped alkyl group or alkenyl group of R ¹⁰¹ include, for example, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and a cyclic group in the above R ¹⁰¹ .

Among the above, R ¹⁰¹ is preferably a cyclic group which may have a substituent, and is more preferably a cyclic hydrocarbon group which may have a substituent.

As a cyclic hydrocarbon group, more specifically, a phenyl group, a naphthyl group, a group having one or more hydrogen atoms removed from a polycycloalkane; a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7); a -SO ₂ - containing cyclic group represented by each of the general formulae (b5-r-1) to (b5-r-4) are preferable, a group having one or more hydrogen atoms removed from a polycycloalkane is more preferable, and an adamantyl group is even more preferable.

In formula (b-1), Y ¹⁰¹ is a divalent linking group containing a single bond or an oxygen atom.

When Y ¹⁰¹ is a divalent linking group containing an oxygen atom, Y ¹⁰¹ may contain an atom other than an oxygen atom. Examples of the atom other than an oxygen atom include a carbon atom, a hydrogen atom, a sulfur atom, a nitrogen atom, and the like.

Examples of the divalent linking group containing an oxygen atom include non-hydrocarbon oxygen atom-containing linking groups such as an oxygen atom (ether bond: -O-), an ester bond (-C(=O)-O-), an oxycarbonyl group (-OC(=O)-), an amide bond (-C(=O)-NH-), a carbonyl group (-C(=O)-), a carbonate bond (-OC(=O)-O-); combinations of the non-hydrocarbon oxygen atom-containing linking groups and alkylene groups; and the like. A sulfonyl group (-SO ₂ -) may be further linked to this combination. Examples of such divalent linking groups containing an oxygen atom include linking groups represented by the following general formulae (y-al-1) to (y-al-7). In addition, in the following general formulas (y-al-1) to (y-al-7), what binds to R ¹⁰¹ in the above formula (b-1) is V' ¹⁰¹ in the following general formulas (y-al-1) to (y-al-7).

[Chemical formula 47]

[In the formula, V' ¹⁰¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and V' ¹⁰² is a divalent saturated hydrocarbon group having 1 to 30 carbon atoms.]

The divalent saturated hydrocarbon group in V' ¹⁰² is preferably an alkylene group having 1 to 30 carbon atoms, more preferably an alkylene group having 1 to 10 carbon atoms, and still more preferably an alkylene group having 1 to 5 carbon atoms.

The alkylene group in V' ¹⁰¹ and V' ¹⁰² may be a linear alkylene group or a branched alkylene group, and a linear alkylene group is preferred.

As the alkylene group in V' ¹⁰¹ and V' ¹⁰² , specifically, a methylene group [-CH ₂ -]; an alkylmethylene group such as -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ -; an ethylene group [-CH ₂ CH ₂ -]; an alkylethylene group such as -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -; a trimethylene group (n-propylene group) [-CH ₂ CH ₂ CH ₂ -]; Examples thereof include alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -; tetramethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ -]; alkyltetramethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -; pentamethylene group [-CH ₂ CH ₂ CH ₂ CH ₂ CH ₂ -], etc.

In addition, some of the methylene groups in the alkylene group in V' ¹⁰¹ or V' ¹⁰² may be substituted with a divalent aliphatic cyclic group having 5 to 10 carbon atoms. The aliphatic cyclic group is preferably a divalent group obtained by further removing one hydrogen atom from the cyclic aliphatic hydrocarbon group of Ra' ³ in the formula (a1-r-1) (monocyclic aliphatic hydrocarbon group, polycyclic aliphatic hydrocarbon group), and a cyclohexylene group, a 1,5-adamantylene group or a 2,6-adamantylene group is more preferable.

For Y ¹⁰¹ , a divalent linking group including an ester bond or a divalent linking group including an ether bond is preferable, and a linking group represented by each of the above formulae (y-al-1) to (y-al-5) is more preferable.

In formula (b-1), V ¹⁰¹ is a single bond, an alkylene group or a fluorinated alkylene group. The alkylene group or fluorinated alkylene group in V ¹⁰¹ preferably has 1 to 4 carbon atoms. Examples of the fluorinated alkylene group in V ¹⁰¹ include groups in which some or all of the hydrogen atoms of the alkylene group in V ¹⁰¹ are replaced with fluorine atoms. Among these, V ¹⁰¹ is preferably a single bond or a fluorinated alkylene group having 1 to 4 carbon atoms, and is more preferably a single bond or a linear fluorinated alkylene group having 1 to 4 carbon atoms.

In formula (b-1), R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. R ¹⁰² is preferably a fluorine atom or a perfluoroalkyl group having 1 to 5 carbon atoms, and is more preferably a fluorine atom.

Specific examples of the anion moiety represented by the above formula (b-1) include, for example, when Y ¹⁰¹ is a single bond, a fluorinated alkyl sulfonate anion such as a trifluoromethanesulfonate anion or a perfluorobutanesulfonate anion; and when Y ¹⁰¹ is a divalent linking group containing an oxygen atom, an anion represented by any of the following formulae (an-1) to (an-3) can be mentioned.

[Chemical formula 48]

[Wherein, R" ¹⁰¹ is an aliphatic cyclic group which may have a substituent, a monovalent heterocyclic group represented by each of the chemical formulas (r-hr-1) to (r-hr-6), a condensed cyclic group represented by the formula (r-br-1) or (r-br-2), or a chain-shaped alkyl group which may have a substituent. R" ¹⁰² is an aliphatic cyclic group which may have a substituent, a condensed cyclic group represented by the formula (r-br-1) or (r-br-2), a lactone-containing cyclic group represented by each of the general formulas (a2-r-1), (a2-r-3) to (a2-r-7), or a -SO ₂ - containing cyclic group represented by each of the general formulas (b5-r-1) to (b5-r-4). R" ¹⁰³ is an aromatic cyclic group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent. V" ¹⁰¹ is a single bond, an alkylene group having 1 to 4 carbon atoms, or a fluorinated alkylene group having 1 to 4 carbon atoms. R ¹⁰² is a fluorine atom or a fluorinated alkyl group having 1 to 5 carbon atoms. v" are each independently an integer of 0 to 3, q" are each independently an integer of 0 to 20, and n" is 0 or 1.]

The aliphatic cyclic group which may have a substituent of R" ¹⁰¹ , R" ¹⁰² and R" ¹⁰³ is preferably a group exemplified as the cyclic aliphatic hydrocarbon group for R ¹⁰¹ in the above formula (b-1). As the substituent, the same groups as the substituents which may substitute the cyclic aliphatic hydrocarbon group for R ¹⁰¹ in the above formula (b-1) can be exemplified.

The aromatic cyclic group which may have a substituent in R" ¹⁰³ is preferably a group exemplified as an aromatic hydrocarbon group in the cyclic hydrocarbon group in R ¹⁰¹ in the above formula (b-1). As the substituent, the same groups as the substituents which may substitute the aromatic hydrocarbon group in R ¹⁰¹ in the above formula (b-1) can be exemplified.

The chain-shaped alkyl group that may have a substituent in R" ¹⁰¹ is preferably a group exemplified as the chain-shaped alkyl group in R ¹⁰¹ in the above formula (b-1).

The chain-shaped alkenyl group that may have a substituent in R" ¹⁰³ is preferably a group exemplified as the chain-shaped alkenyl group in R ¹⁰¹ in the above formula (b-1).

· (b-2) Anion in the component

In formula (b-2), R ¹⁰⁴ and R ¹⁰⁵ each independently represent a cyclic group which may have a substituent, a chain-shaped alkyl group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent, and examples thereof include the same groups as R ¹⁰¹ in formula (b-1). However, R ¹⁰⁴ and R ¹⁰⁵ may be bonded to each other to form a ring.

R ¹⁰⁴ and R ¹⁰⁵ are preferably a chain-like alkyl group which may have a substituent, and are more preferably a linear or branched alkyl group, or a linear or branched fluorinated alkyl group.

The number of carbon atoms of the chain-shaped alkyl group is preferably 1 to 10, more preferably 1 to 7, and even more preferably 1 to 3. The number of carbon atoms of the chain-shaped alkyl group of R ¹⁰⁴ and R ¹⁰⁵ is preferably smaller within the range of the above-mentioned number of carbon atoms, for reasons such as better solubility in a resist solvent. In addition, in the chain-shaped alkyl group of R ¹⁰⁴ and R ¹⁰⁵ , the greater the number of hydrogen atoms substituted with fluorine atoms, the stronger the acid strength becomes, and transparency to high-energy light or electron beams of 250 nm or less is improved, which is preferable. The ratio of fluorine atoms in the above chain-shaped alkyl group, i.e., the fluorination rate, is preferably 70 to 100%, more preferably 90 to 100%, and most preferably, it is a perfluoroalkyl group in which all hydrogen atoms are replaced with fluorine atoms.

In formula (b-2), V ¹⁰² and V ¹⁰³ are each independently a single bond, an alkylene group, or a fluorinated alkylene group, and examples thereof include those identical to V ¹⁰¹ in formula (b-1).

In formula (b-2), L ¹⁰¹ and L ¹⁰² are each independently a single bond or an oxygen atom.

· (b-3) Anion in the component

In formula (b-3), R ¹⁰⁶ to R ¹⁰⁸ are each independently a cyclic group which may have a substituent, a chain-shaped alkyl group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent, and examples thereof include the same groups as R ¹⁰¹ in formula (b-1).

In formula (b-3), L ¹⁰³ to L ¹⁰⁵ are each independently a single bond, -CO- or -SO ₂ -.

Among the above, as the anion part of component (B), the anion in component (b-1) is preferable.

{Cation section}

In the above formulas (b-1), (b-2), and (b-3), M' ^m+ represents an onium cation having a valence of m. Among these, sulfonium cation and iodonium cation are preferable.

m is an integer greater than or equal to 1.

As a preferable cation moiety ((M' ^m＋ ) _1/m ), organic cations represented by the following general formulas (ca-1) to (ca-3) can be mentioned.

[Chemical Formula 49]

[In the formula, R ²⁰¹ to R ²⁰⁷ independently represent an aryl group, an alkyl group, or an alkenyl group which may have a substituent. R ²⁰¹ to R ²⁰³ and R ²⁰⁶ to R ²⁰⁷ may be bonded to each other to form a ring with the sulfur atom in the formula. R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms. R ²¹⁰ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO ₂ -containing cyclic group which may have a substituent. L ²⁰¹ represents -C(=O)- or -C(=O)-O-.]

Among the above general formulae (ca-1) to (ca-3), the aryl group in R ²⁰¹ to R ²⁰⁷ includes an unsubstituted aryl group having 6 to 20 carbon atoms, and a phenyl group and a naphthyl group are preferable.

The alkyl group for R ²⁰¹ to R ²⁰⁷ is preferably a chain-shaped or cyclic alkyl group having 1 to 30 carbon atoms.

As for the alkenyl group in R ²⁰¹ to R ²⁰⁷ , one having 2 to 10 carbon atoms is preferable.

Substituents that may be present in R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ include, for example, an alkyl group, a halogen atom, a halogenated alkyl group, a carbonyl group, a cyano group, an amino group, an aryl group, and groups represented by the following general formulae (ca-r-1) to (ca-r-7), respectively.

[Chemical formula 50]

[In the formula, R' ²⁰¹ is, each independently, a hydrogen atom, a cyclic group which may have a substituent, a chain-shaped alkyl group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent.]

Cyclic groups that may have substituents:

The cyclic group is preferably a cyclic hydrocarbon group, and the cyclic hydrocarbon group may be an aromatic hydrocarbon group or an aliphatic hydrocarbon group. The aliphatic hydrocarbon group means a hydrocarbon group that does not have aromaticity. In addition, the aliphatic hydrocarbon group may be saturated or unsaturated, and usually, it is preferable that it is saturated.

The aromatic hydrocarbon group in R' ²⁰¹ is a hydrocarbon group having an aromatic ring. The aromatic hydrocarbon group preferably has 3 to 30 carbon atoms, more preferably 5 to 30 carbon atoms, still more preferably 5 to 20 carbon atoms, particularly preferably 6 to 15 carbon atoms, and most preferably 6 to 10 carbon atoms. However, the number of carbon atoms does not include the number of carbon atoms in the substituent.

Specific examples of the aromatic ring possessed by the aromatic hydrocarbon group in R' ²⁰¹ include benzene, fluorene, naphthalene, anthracene, phenanthrene, biphenyl, or an aromatic heterocycle in which some of the carbon atoms constituting these aromatic rings are replaced with heteroatoms. Examples of the heteroatom in the aromatic heterocycle include an oxygen atom, a sulfur atom, a nitrogen atom, and the like.

Specific examples of the aromatic hydrocarbon group for R' ²⁰¹ include a group in which one hydrogen atom has been removed from the aromatic ring (aryl group: for example, a phenyl group, a naphthyl group, etc.), a group in which one hydrogen atom of the aromatic ring has been replaced with an alkylene group (for example, an arylalkyl group such as a benzyl group, a phenethyl group, a 1-naphthylmethyl group, a 2-naphthylmethyl group, a 1-naphthylethyl group, a 2-naphthylethyl group, etc.). The alkylene group (alkyl chain in the arylalkyl group) preferably has 1 to 4 carbon atoms, more preferably 1 to 2 carbon atoms, and particularly preferably 1 carbon atom.

The cyclic aliphatic hydrocarbon group in R' ²⁰¹ may be an aliphatic hydrocarbon group containing a ring in its structure.

Among these structures, examples of aliphatic hydrocarbon groups containing a ring include an alicyclic hydrocarbon group (a group in which one hydrogen atom is removed from an aliphatic hydrocarbon ring), a group in which an alicyclic hydrocarbon group is bonded to the end of a linear or branched aliphatic hydrocarbon group, and a group in which an alicyclic hydrocarbon group is interposed in the middle of a linear or branched aliphatic hydrocarbon group.

The above-mentioned alicyclic hydrocarbon group preferably has 3 to 20 carbon atoms, and more preferably has 3 to 12 carbon atoms.

The above-mentioned alicyclic hydrocarbon group may be a polycyclic group or a monocyclic group. As the monocyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a monocycloalkane is preferable. As the monocycloalkane, a group having 3 to 6 carbon atoms is preferable, and specific examples thereof include cyclopentane and cyclohexane. As the polycyclic alicyclic hydrocarbon group, a group obtained by removing one or more hydrogen atoms from a polycycloalkane is preferable, and the polycycloalkane is preferably a group having 7 to 30 carbon atoms. Among these, examples of the polycycloalkane include polycycloalkanes having a polycyclic skeleton of a bridged ring system, such as adamantane, norbornane, isobornane, tricyclodecane, and tetracyclododecane; A polycycloalkane having a polycyclic skeleton of a condensed ring system, such as a cyclic group having a steroid skeleton, is more preferable.

Among these, as the cyclic aliphatic hydrocarbon group for R' ²⁰¹ , a group having at least one hydrogen atom removed from a monocycloalkane or a polycycloalkane is preferable, a group having one hydrogen atom removed from a polycycloalkane is more preferable, an adamantyl group and a norbornyl group are particularly preferable, and an adamantyl group is most preferable.

The linear or branched aliphatic hydrocarbon group that may be bonded to an alicyclic hydrocarbon group preferably has 1 to 10 carbon atoms, more preferably 1 to 6 carbon atoms, still more preferably 1 to 4 carbon atoms, and particularly preferably 1 to 3 carbon atoms.

As the linear aliphatic hydrocarbon group, a linear alkylene group is preferable, and specific examples thereof include a methylene group [-CH ₂ -], an ethylene group [-(CH ₂ ) ₂ -], a trimethylene group [-(CH ₂ ) ₃ -], a tetramethylene group [-(CH ₂ ) ₄ -], a pentamethylene group [-(CH ₂ ) ₅ -], and the like.

As the branched-chain aliphatic hydrocarbon group, a branched-chain alkylene group is preferable, and specifically, alkylmethylene groups such as -CH(CH ₃ )-, -CH(CH ₂ CH ₃ )-, -C(CH ₃ ) ₂ -, -C(CH ₃ )(CH ₂ CH ₃ )-, -C(CH ₃ )(CH ₂ CH ₂ CH ₃ )-, -C(CH ₂ CH ₃ ) ₂ -; alkylethylene groups such as -CH(CH ₃ )CH ₂ -, -CH(CH ₃ )CH(CH ₃ )-, -C(CH ₃ ) ₂ CH ₂ -, -CH(CH ₂ CH ₃ )CH ₂ -, -C(CH ₂ CH ₃ ) ₂ -CH ₂ -; Examples thereof include alkyltrimethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ -, and the like; alkylalkylene groups such as alkyltetramethylene groups such as -CH(CH ₃ )CH ₂ CH ₂ CH ₂ -, -CH ₂ CH(CH ₃ )CH ₂ CH ₂ -, and the like. As the alkyl group in the alkylalkylene group, a linear alkyl group having 1 to 5 carbon atoms is preferable.

In addition, the cyclic hydrocarbon group in R' ²⁰¹ may contain a heteroatom such as a heterocyclic ring. Specifically, examples thereof include lactone-containing cyclic groups represented by the general formulae (a2-r-1) to (a2-r-7) respectively, -SO ₂ - containing cyclic groups represented by the general formulae (b5-r-1) to (b5-r-4) respectively, and other heterocyclic groups represented by the chemical formulae (r-hr-1) to (r-hr-16) respectively.

Substituents in the cyclic group of R' ²⁰¹ include, for example, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, and the like.

As an alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms is preferable, and a methyl group, an ethyl group, a propyl group, an n-butyl group, and a tert-butyl group are most preferable.

As an alkoxy group as a substituent, an alkoxy group having 1 to 5 carbon atoms is preferable, a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, a tert-butoxy group are more preferable, and a methoxy group and an ethoxy group are most preferable.

As a halogen atom as a substituent, a fluorine atom is preferable.

As a halogenated alkyl group as a substituent, an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an n-butyl group, a tert-butyl group, etc., in which some or all of the hydrogen atoms are replaced with the halogen atoms, can be exemplified.

A carbonyl group as a substituent is a group that substitutes a methylene group (-CH ₂ -) that constitutes a cyclic hydrocarbon group.

Chain-shaped alkyl group which may have a substituent:

The chain-type alkyl group of R' ²⁰¹ may be either linear or branched.

As for the straight-chain alkyl group, those having 1 to 20 carbon atoms are preferable, those having 1 to 15 carbon atoms are more preferable, and those having 1 to 10 carbon atoms are most preferable.

As the branched-chain alkyl group, those having 3 to 20 carbon atoms are preferable, those having 3 to 15 carbon atoms are more preferable, and those having 3 to 10 carbon atoms are most preferable. Specifically, examples thereof include a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

Chain-shaped alkenyl group which may have a substituent:

The chain-shaped alkenyl group of R' ²⁰¹ may be either linear or branched, and preferably has 2 to 10 carbon atoms, more preferably 2 to 5 carbon atoms, still more preferably 2 to 4 carbon atoms, and particularly preferably 3 carbon atoms. Examples of the linear alkenyl group include a vinyl group, a propenyl group (allyl group), a butynyl group, and the like. Examples of the branched alkenyl group include a 1-methylvinyl group, a 2-methylvinyl group, a 1-methylpropenyl group, and a 2-methylpropenyl group.

Among the chain-shaped alkenyl groups, a linear alkenyl group is preferable, a vinyl group or a propenyl group is more preferable, and a vinyl group is particularly preferable.

Substituents in the chain-shaped alkyl group or alkenyl group of R' ²⁰¹ include, for example, an alkoxy group, a halogen atom, a halogenated alkyl group, a hydroxyl group, a carbonyl group, a nitro group, an amino group, and a cyclic group in the above R' ²⁰¹ .

The cyclic group which may have a substituent of R' ²⁰¹ , the chain-shaped alkyl group which may have a substituent, or the chain-shaped alkenyl group which may have a substituent, in addition to those described above, may also include the same acid-labile groups represented by the formula (a1-r-2) described above as the cyclic group which may have a substituent or the chain-shaped alkyl group which may have a substituent.

Among these, R' ²⁰¹ is preferably a cyclic group which may have a substituent, and is more preferably a cyclic hydrocarbon group which may have a substituent. More specifically, for example, a phenyl group, a naphthyl group, a group in which one or more hydrogen atoms have been removed from a polycycloalkane; a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7); a -SO ₂ - containing cyclic group represented by each of the general formulae (b5-r-1) to (b5-r-4), etc. are preferable.

In the above general formulas (ca-1) to (ca-3), when R ²⁰¹ to R ²⁰³ and R ²⁰⁶ to R ²⁰⁷ are bonded to each other to form a ring with the sulfur atom in the formula, they may be bonded via a heteroatom such as a sulfur atom, an oxygen atom, or a nitrogen atom; a carbonyl group, -SO-, -SO ₂ -, -SO ₃ -, -COO-, -CONH- or -N (R _N )- (wherein R _N is an alkyl group having 1 to 5 carbon atoms). Among the rings formed, one ring including the sulfur atom in the formula in its ring skeleton is preferably a 3 to 10-membered ring including the sulfur atom, and is particularly preferably a 5 to 7-membered ring. Specific examples of the rings formed include, for example, a thiophene ring, a thiazole ring, a benzothiophene ring, a dibenzothiophene ring, a 9H-thioxanthene ring, a thioxanthone ring, a thianthrene ring, a phenoxanthine ring, a tetrahydrothiophenium ring, a tetrahydrothiopyranium ring, and the like.

R ²⁰⁸ to R ²⁰⁹ each independently represent a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and when they are alkyl groups, they may be bonded to each other to form a ring.

R ²¹⁰ is an aryl group which may have a substituent, an alkyl group which may have a substituent, an alkenyl group which may have a substituent, or a -SO ₂ - containing cyclic group which may have a substituent.

As the aryl group in R ²¹⁰ , an unsubstituted aryl group having 6 to 20 carbon atoms can be mentioned, and a phenyl group or a naphthyl group is preferable.

The alkyl group in R ²¹⁰ is preferably a chain-shaped or cyclic alkyl group having 1 to 30 carbon atoms.

As for the alkenyl group in R ²¹⁰ , one having 2 to 10 carbon atoms is preferable.

As the -SO ₂ -containing cyclic group which may have a substituent in R ²¹⁰ , a "-SO ₂ -containing polycyclic group" is preferable, and a group represented by the above general formula (b5-r-1) is more preferable.

As a preferable cation represented by the above formula (ca-1), specifically, cations represented by the following chemical formulas (ca-1-1) to (ca-1-70) can be mentioned.

[Chemical Formula 51]

[Chemical formula 52]

[Chemical formula 53]

[In the formula, g1, g2, and g3 represent the number of repetitions, g1 is an integer from 1 to 5, g2 is an integer from 0 to 20, and g3 is an integer from 0 to 20.]

[Chemical formula 54]

[Chemical formula 55]

[Chemical formula 56]

[In the formula, R" ²⁰¹ is a hydrogen atom or a substituent, and the substituent is the same as the substituents that may be included in R ²⁰¹ to R ²⁰⁷ and R ²¹⁰ to R ^212. ]

In the resist composition of the present embodiment, component (B) may be used alone or in combination of two or more types.

When the resist composition contains component (B), the content of component (B) in the resist composition is preferably less than 50 parts by mass, more preferably 10 to 40 parts by mass, and even more preferably 20 to 40 parts by mass, with respect to 100 parts by mass of component (A).

(B) By setting the content of the component within the above preferred range, pattern formation is sufficiently carried out. In addition, when each component of the resist composition is dissolved in an organic solvent, it is easy to obtain a uniform solution, and the preservation stability as a resist composition is improved, which is preferable.

≪Base component (D)≫

The resist composition of the present embodiment preferably contains, in addition to component (A), a base component (hereinafter also referred to as “component (D)”) that traps acid generated by exposure (i.e., controls diffusion of acid). Component (D) acts as an acid diffusion controller (acid diffusion control agent) that traps acid generated by exposure in the resist composition.

(D) As the component, for example, a photodegradable base (D1) (hereinafter referred to as “(D1) component”) that decomposes by exposure and loses acid diffusion controllability, a nitrogen-containing organic compound (D2) (hereinafter referred to as “(D2) component”) that does not correspond to the (D1) component, etc. can be mentioned. Of these, a photodegradable base ((D1) component) is preferable in that roughness reduction property tends to increase. In addition, by containing the (D1) component, it becomes easy to enhance both the characteristics of high sensitivity and suppression of occurrence of coating defects.

· (D1) About the ingredients

By using a resist composition containing the (D1) component, when forming a resist pattern, the contrast between the exposed portion and the unexposed portion of the resist film can be further improved.

The (D1) component is not particularly limited as long as it decomposes by exposure and loses acid diffusion controllability, and is preferably at least one compound selected from the group consisting of a compound represented by the following general formula (d1-1) (hereinafter referred to as “(d1-1) component”), a compound represented by the following general formula (d1-2) (hereinafter referred to as “(d1-2) component”), and a compound represented by the following general formula (d1-3) (hereinafter referred to as “(d1-3) component”).

Components (d1-1) to (d1-3) do not act as a ?? agent in the exposed portion of the resist film because they decompose and lose acid diffusion controllability (basicity), but act as a ?? agent in the unexposed portion of the resist film.

[Chemical formula 57]

[In the formula, Rd ¹ to Rd ⁴ are a cyclic group which may have a substituent, a chain-shaped alkyl group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent. However, in Rd ² in the formula (d1-2), no fluorine atom is bonded to the carbon atom adjacent to the S atom. Yd ¹ is a single bond or a divalent linking group. m is an integer greater than or equal to 1, and M ^m+ are each independently an organic cation having a valence of m.]

{(d1-1) component}

·· No, not the Anion Department

In formula (d1-1), Rd ¹ is a cyclic group which may have a substituent, a chain-shaped alkyl group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent, and examples thereof include the same as R' ²⁰¹ .

Among these, as Rd ¹ , an aromatic hydrocarbon group which may have a substituent, an aliphatic cyclic group which may have a substituent, or a chain-shaped alkyl group which may have a substituent is preferable. Examples of the substituent which these groups may have include a hydroxyl group, an oxo group, an alkyl group, an aryl group, a fluorine atom, a fluorinated alkyl group, a lactone-containing cyclic group represented by each of the general formulae (a2-r-1) to (a2-r-7), an ether bond, an ester bond, or a combination thereof. When an ether bond or an ester bond is included as a substituent, an alkylene group may be interposed, and the substituent in this case is preferably a linking group represented by each of the formulae (y-al-1) to (y-al-5). In addition, in a case where the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-shaped alkyl group in Rd ¹ has, as a substituent, a linking group represented by each of the general formulae (y-al-1) to (y-al-7), in the general formulae (y-al-1) to (y-al-7), the carbon atom constituting the aromatic hydrocarbon group, the aliphatic cyclic group, or the chain-shaped alkyl group in Rd ¹ in formula (d3-1) is V' ¹⁰¹ in the general formulae (y-al-1) to (y-al-7).

As the above aromatic hydrocarbon group, a phenyl group, a naphthyl group, or a polycyclic structure including a bicyclooctane skeleton (a polycyclic structure composed of a bicyclooctane skeleton and a ring structure other than this) can be preferably mentioned.

As the above aliphatic cyclic group, it is more preferable to use a group obtained by removing one or more hydrogen atoms from a polycycloalkane such as adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane.

As the above-mentioned chain-shaped alkyl group, those having 1 to 10 carbon atoms are preferable, and specific examples thereof include linear alkyl groups such as a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, a heptyl group, an octyl group, a nonyl group, and a decyl group; and branched-chain alkyl groups such as a 1-methylethyl group, a 1-methylpropyl group, a 2-methylpropyl group, a 1-methylbutyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 1-ethylbutyl group, a 2-ethylbutyl group, a 1-methylpentyl group, a 2-methylpentyl group, a 3-methylpentyl group, and a 4-methylpentyl group.

When the above chain-shaped alkyl group is a fluorinated alkyl group having a fluorine atom or a fluorinated alkyl group as a substituent, the number of carbon atoms of the fluorinated alkyl group is preferably 1 to 11, more preferably 1 to 8, and even more preferably 1 to 4. The fluorinated alkyl group may contain an atom other than a fluorine atom. Examples of the atom other than a fluorine atom include an oxygen atom, a sulfur atom, a nitrogen atom, and the like.

Below, preferred specific examples of the anion portion of the (d1-1) component are shown.

[Chemical formula 58]

·· Cation section

In formula (d1-1), M ^m＋ is an organic cation of valence m.

As the organic cation of M ^m＋ , the same cations as those represented by the general formulae (ca-1) to (ca-3) are preferably mentioned, the cation represented by the general formula (ca-1) is more preferable, and the cations represented by the general formulae (ca-1-1) to (ca-1-113) are further preferable.

(d1-1) One component may be used alone, or two or more components may be used in combination.

{(d1-2) component}

·· No, not the Anion Department

In formula (d1-2), Rd ² is a cyclic group which may have a substituent, a chain-shaped alkyl group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent, and examples thereof include the same as R' ²⁰¹ .

However, in Rd ² , the carbon atom adjacent to the S atom is not bonded to a fluorine atom (is not substituted with fluorine). As a result, the anion of the (d1-2) component becomes a suitable weak acid anion, and the ??charging ability as the (D) component is improved.

As for Rd ² , it is preferable that it is a chain-shaped alkyl group which may have a substituent, or an aliphatic cyclic group which may have a substituent, and it is more preferable that it is an aliphatic cyclic group which may have a substituent.

As for the chain-shaped alkyl group, those having 1 to 10 carbon atoms are preferable, and those having 3 to 10 carbon atoms are more preferable.

As the aliphatic cyclic group, a group having one or more hydrogen atoms removed from adamantane, norbornane, isobornane, tricyclodecane, tetracyclododecane, etc. (which may have a substituent); a group having one or more hydrogen atoms removed from camphor is more preferable.

The hydrocarbon group of Rd ² may have a substituent, and examples of the substituent include the same substituents as those that the hydrocarbon group (aromatic hydrocarbon group, aliphatic cyclic group, chain-shaped alkyl group) of Rd ¹ of the above formula (d1-1) may have.

Below, preferred specific examples of the anion portion of the (d1-2) component are shown.

[Chemical formula 59]

·· Cation section

In formula (d1-2), M ^m+ is an organic cation with valence m and is the same as M ^m+ in formula (d1-1).

(d1-2) One component may be used alone, or two or more components may be used in combination.

{(d1-3) components}

·· No, not the Anion Department

In formula (d1-3), Rd ³ is a cyclic group which may have a substituent, a chain-shaped alkyl group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent, and examples thereof include the same as R' ²⁰¹ above, and it is preferably a cyclic group containing a fluorine atom, a chain-shaped alkyl group, or a chain-shaped alkenyl group. Among these, a fluorinated alkyl group is preferable, and one which is the same as the fluorinated alkyl group of Rd ¹ above is more preferable.

In formula (d1-3), Rd ⁴ is a cyclic group which may have a substituent, a chain-shaped alkyl group which may have a substituent, or a chain-shaped alkenyl group which may have a substituent, and examples thereof include the same as R' ²⁰¹ .

Among these, an alkyl group, an alkoxy group, an alkenyl group, or a cyclic group that may have a substituent is preferable.

The alkyl group in Rd ⁴ is preferably a linear or branched alkyl group having 1 to 5 carbon atoms, and specific examples thereof include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a tert-butyl group, a pentyl group, an isopentyl group, a neopentyl group, and the like. Some of the hydrogen atoms in the alkyl group in Rd ⁴ may be substituted with a hydroxyl group, a cyano group, or the like.

The alkoxy group in Rd ⁴ is preferably an alkoxy group having 1 to 5 carbon atoms, and specific examples of the alkoxy group having 1 to 5 carbon atoms include a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, and a tert-butoxy group. Among these, a methoxy group and an ethoxy group are preferable.

The alkenyl group in Rd ⁴ may be the same as the alkenyl group in R' ²⁰¹ , and a vinyl group, a propenyl group (allyl group), a 1-methylpropenyl group, or a 2-methylpropenyl group are preferable. These groups may further have, as a substituent, an alkyl group having 1 to 5 carbon atoms or a halogenated alkyl group having 1 to 5 carbon atoms.

The cyclic group in Rd ⁴ can be the same as the cyclic group in R' ²⁰¹ , and is preferably an alicyclic group having one or more hydrogen atoms removed from a cycloalkane such as cyclopentane, cyclohexane, adamantane, norbornane, isobornane, tricyclodecane, or tetracyclododecane, or an aromatic group such as a phenyl group or a naphthyl group. When Rd ⁴ is an alicyclic group, the resist composition dissolves well in an organic solvent, whereby the lithography characteristics become good. Furthermore, when Rd ⁴ is an aromatic group, in lithography using EUV or the like as an exposure light source, the resist composition has excellent light absorption efficiency, and the sensitivity and lithography characteristics become good.

In formula (d1-3), Yd ¹ is a single bond or a divalent linking group.

The divalent linking group in Yd ¹ is not particularly limited, but may include a divalent hydrocarbon group (aliphatic hydrocarbon group, aromatic hydrocarbon group) which may have a substituent, a divalent linking group containing a hetero atom, etc. These may be the same as the divalent hydrocarbon group which may have a substituent, and the divalent linking group containing a hetero atom, which are exemplified in the explanation of the divalent linking group in Ya ²¹ in the above formula (a2-1).

As for Yd ¹ , it is preferable that it is a carbonyl group, an ester bond, an amide bond, an alkylene group or a combination of these. As the alkylene group, it is more preferable that it is a linear or branched alkylene group, and it is still more preferable that it is a methylene group or an ethylene group.

Below, preferred specific examples of the anion portion of the (d1-3) component are shown.

[Chemical formula 60]

[Chemical formula 61]

·· Cation section

In formula (d1-3), M ^m+ is an organic cation with valence m and is the same as M ^m+ in formula (d1-1).

(d1-3) One component may be used alone, or two or more components may be used in combination.

(D1) Component may use only one of the components (d1-1) to (d1-3) above, or may use two or more of them in combination.

When the resist composition contains component (D1), the content of component (D1) in the resist composition is preferably 0.5 to 25 parts by mass, more preferably 1 to 20 parts by mass, and still more preferably 3 to 15 parts by mass, with respect to 100 parts by mass of component (A1).

(D1) When the content of the component is equal to or higher than the preferred lower limit, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is equal to or lower than the upper limit, sensitivity can be maintained well and throughput is also excellent.

In the resist composition of the present embodiment, it is preferable that the component (D1) contains the above-mentioned component (d1-1).

Among the entire (D) component contained in the resist composition of the present embodiment, the content of the (d1-1) component is preferably 50 mass% or more, preferably 70 mass% or more, and more preferably 90 mass% or more, and the (D) component may be composed solely of the compound (d1-1) component.

(D1) Method for manufacturing the component:

The method for producing the above components (d1-1) and (d1-2) is not particularly limited, and can be produced by a known method.

In addition, the method for manufacturing the (d1-3) component is not particularly limited, and is manufactured in the same manner as, for example, the method described in US2012-0149916.

· (D2) About the component

(D) As a component, a nitrogen-containing organic compound component that does not correspond to the above (D1) component (hereinafter referred to as “(D2) component”) may be contained.

(D2) As a component, it acts as an acid diffusion control agent, and furthermore, as long as it does not correspond to the (D1) component, it is not particularly limited and any known component may be used. Among these, an aliphatic amine is preferable, and among these, a secondary aliphatic amine or a tertiary aliphatic amine is more preferable.

An aliphatic amine is an amine having one or more aliphatic groups, and it is preferable that the aliphatic groups have 1 to 12 carbon atoms.

As aliphatic amines, examples thereof include amines (alkylamines or alkylalcoholamines) or cyclic amines in which at least one of the hydrogen atoms of ammonia _NH3 is replaced with an alkyl group or hydroxyalkyl group having 12 or fewer carbon atoms.

Specific examples of alkylamines and alkylalcoholamines include monoalkylamines such as n-hexylamine, n-heptylamine, n-octylamine, n-nonylamine, and n-decylamine; dialkylamines such as diethylamine, di-n-propylamine, di-n-heptylamine, di-n-octylamine, and dicyclohexylamine; trialkylamines such as trimethylamine, triethylamine, tri-n-propylamine, tri-n-butylamine, tri-n-pentylamine, tri-n-hexylamine, tri-n-heptylamine, tri-n-octylamine, tri-n-nonylamine, tri-n-decylamine, and tri-n-dodecylamine; and alkylalcoholamines such as diethanolamine, triethanolamine, diisopropanolamine, triisopropanolamine, di-n-octanolamine, and tri-n-octanolamine. Among these, trialkylamines having 6 to 30 carbon atoms are more preferable, and tri-n-pentylamine or tri-n-octylamine is particularly preferable.

As a cyclic amine, for example, a heterocyclic compound containing a nitrogen atom as a heteroatom can be mentioned. The heterocyclic compound can be monocyclic (aliphatic monocyclic amine) or polycyclic (aliphatic polycyclic amine).

As aliphatic monocyclic amines, specific examples include piperidine and piperazine.

As the aliphatic polycyclic amine, those having 6 to 10 carbon atoms are preferable, and specific examples thereof include 1,5-diazabicyclo[4.3.0]-5-nonene, 1,8-diazabicyclo[5.4.0]-7-undecene, hexamethylenetetramine, and 1,4-diazabicyclo[2.2.2]octane.

Other aliphatic amines include tris(2-methoxymethoxyethyl)amine, tris{2-(2-methoxyethoxy)ethyl}amine, tris{2-(2-methoxyethoxymethoxy)ethyl}amine, tris{2-(1-methoxyethoxy)ethyl}amine, tris{2-(1-ethoxyethoxy)ethyl}amine, tris{2-(1-ethoxypropoxy)ethyl}amine, tris[2-{2-(2-hydroxyethoxy)ethoxy}ethyl]amine, and triethanolamine triacetate, with triethanolamine triacetate being preferred.

Additionally, as the (D2) component, an aromatic amine may be used.

Aromatic amines include 4-dimethylaminopyridine, pyrrole, indole, pyrazole, imidazole or derivatives thereof, tribenzylamine, 2,6-diisopropylaniline, N-tert-butoxycarbonylpyrrolidine, 2,6-di-tert-butylpyridine, etc.

Among the above, the (D2) component is preferably an alkylamine, and a trialkylamine having 6 to 30 carbon atoms is more preferable.

(D2) One component may be used alone, or two or more components may be used in combination.

When the resist composition contains component (D2), the content of component (D2) in the resist composition is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 5 parts by mass, and still more preferably 0.5 to 5 parts by mass, with respect to 100 parts by mass of component (A1).

(D2) When the content of the component is equal to or higher than the preferred lower limit, particularly good lithography characteristics and resist pattern shape are easily obtained. On the other hand, when it is equal to or lower than the upper limit, sensitivity can be maintained well and throughput is also excellent.

≪At least one compound (E) selected from the group consisting of organic carboxylic acids, and phosphorus oxo acids and derivatives thereof≫

The resist composition of the present embodiment may contain, as an optional component, at least one compound (E) selected from the group consisting of organic carboxylic acids, phosphorus oxo acids and derivatives thereof (hereinafter referred to as “component (E)”) for the purpose of preventing sensitivity deterioration or improving the resist pattern shape, stability over time after exposure, etc.

As organic carboxylic acids, specific examples thereof include acetic acid, malonic acid, citric acid, malic acid, succinic acid, benzoic acid, salicylic acid, etc., and among them, salicylic acid is preferable.

Examples of oxoacids of phosphorus include phosphoric acid, phosphonic acid, and phosphinic acid, and among these, phosphonic acid is particularly preferable.

In the resist composition of the present embodiment, component (E) may be used alone or in combination of two or more types.

When the resist composition contains component (E), the content of component (E) is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 3 parts by mass, with respect to 100 parts by mass of component (A). By setting it within the above range, the lithography characteristics are further improved.

≪Fluorine additive component (F)≫

The resist composition of the present embodiment may contain a fluorine additive component (hereinafter referred to as “component (F)”) as a hydrophobic resin. Component (F) is used to impart water repellency to the resist film, and can improve lithography characteristics by being used as a separate resin from component (A). As the component (F), for example, a fluorine-containing polymer compound described in Japanese Patent Application Laid-Open No. 2010-002870, Japanese Patent Application Laid-Open No. 2010-032994, Japanese Patent Application Laid-Open No. 2010-277043, Japanese Patent Application Laid-Open No. 2011-13569, or Japanese Patent Application Laid-Open No. 2011-128226 can be used.

(F) More specifically, as the component, a polymer having a structural unit (f1) represented by the following general formula (f1-1) can be mentioned. As the polymer, a polymer (homopolymer) composed solely of the structural unit (f1) represented by the following formula (f1-1); a copolymer of the structural unit (f1) and the structural unit (a1); a copolymer of the structural unit (f1) and a structural unit derived from acrylic acid or methacrylic acid and the structural unit (a1) is preferable, and a copolymer of the structural unit (f1) and the structural unit (a1) is more preferable. Here, as the structural unit (a1) copolymerized with the structural unit (f1), a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate is preferable, a structural unit derived from 1-methyl-1-adamantyl (meth)acrylate is preferable, and a structural unit derived from 1-ethyl-1-cyclooctyl (meth)acrylate is more preferable.

[Chemical formula 62]

[In the formula, R is the same as defined above, Rf ¹⁰² and Rf ¹⁰³ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group having 1 to 5 carbon atoms, and Rf ¹⁰² and Rf ¹⁰³ may be the same or different. nf ¹ is an integer of 0 to 5, and Rf ¹⁰¹ is an organic group containing a fluorine atom.]

In formula (f1-1), R bonded to the carbon atom at the α position is the same as above. As R, a hydrogen atom or a methyl group is preferable.

In formula (f1-1), the halogen atom of Rf ¹⁰² and Rf ¹⁰³ is preferably a fluorine atom. The alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ includes the same groups as the alkyl group having 1 to 5 carbon atoms of R, and a methyl group or an ethyl group is preferably used. Specifically, the halogenated alkyl group having 1 to 5 carbon atoms of Rf ¹⁰² and Rf ¹⁰³ includes groups in which some or all of the hydrogen atoms of the alkyl group having 1 to 5 carbon atoms are replaced with halogen atoms. The halogen atom is preferably a fluorine atom. Among these, as Rf ¹⁰² and Rf ¹⁰³ , a hydrogen atom, a fluorine atom, or an alkyl group having 1 to 5 carbon atoms is preferable, a hydrogen atom, a fluorine atom, a methyl group, or an ethyl group is more preferable, and a hydrogen atom is even more preferable.

In formula (f1-1), nf ¹ is an integer from 0 to 5, preferably an integer from 0 to 3, and more preferably 1 or 2.

In formula (f1-1), Rf ¹⁰¹ is an organic group containing a fluorine atom, and is preferably a hydrocarbon group containing a fluorine atom.

The hydrocarbon group containing a fluorine atom may be any of a linear, branched or cyclic type, and preferably has 1 to 20 carbon atoms, more preferably 1 to 15 carbon atoms, and particularly preferably 1 to 10 carbon atoms.

In addition, it is preferable that the hydrocarbon group containing a fluorine atom has 25% or more of the hydrogen atoms in the hydrocarbon group fluorinated, more preferably 50% or more of the hydrogen atoms are fluorinated, and particularly preferably 60% or more of the hydrogen atoms are fluorinated, from the viewpoint of increasing the hydrophobicity of the resist film during immersion exposure.

Among these, as Rf ¹⁰¹ , a fluorinated hydrocarbon group having 1 to 6 carbon atoms is more preferable, and a trifluoromethyl group, -CH ₂ -CF ₃ , -CH ₂ -CF ₂ -CF ₃ , -CH(CF ₃ ) ₂ , -CH ₂ -CH ₂ -CF ₃ , -CH ₂ -CH ₂ -CF ₂ -CF ₂ -CF ₂ -CF ₃ are particularly preferable.

(F) The weight average molecular weight (Mw) of the component (based on polystyrene conversion by gel permeation chromatography) is preferably 1,000 to 50,000, more preferably 5,000 to 40,000, and most preferably 10,000 to 30,000. If it is equal to or less than the upper limit of this range, there is sufficient solubility in a resist solvent for use as a resist, and if it is equal to or greater than the lower limit of this range, the water repellency of the resist film is good.

(F) The dispersion ratio (Mw/Mn) of the component is preferably 1.0 to 5.0, more preferably 1.0 to 3.0, and most preferably 1.0 to 2.5.

In the resist composition of the present embodiment, component (F) may be used alone or in combination of two or more types.

When the resist composition contains component (F), the content of component (F) is preferably 0.5 to 10 parts by mass, more preferably 1 to 10 parts by mass, with respect to 100 parts by mass of component (A).

≪Organic solvent component (S)≫

The resist composition of the present embodiment can be manufactured by dissolving the resist material in an organic solvent component (hereinafter referred to as “component (S)”).

(S) As a component, any component that can dissolve each component used and make a uniform solution may be used, and any one of those known as a solvent for a conventional chemically amplified resist composition may be appropriately selected and used.

(S) As the component, for example, lactones such as γ-butyrolactone; ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl-n-pentyl ketone, methyl isopentyl ketone, and 2-heptanone; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, or dipropylene glycol monoacetate; derivatives of polyhydric alcohols such as monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, and monobutyl ether of the above polyhydric alcohols or compounds having an ester bond, or compounds having an ether bond such as monophenyl ether [of these, propylene glycol monomethyl ether acetate (PGMEA) and propylene glycol monomethyl ether (PGME) are preferable]; Examples thereof include cyclic ethers such as dioxane; esters such as methyl lactate, ethyl lactate (EL), methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate, methyl methoxypropionate, and ethyl ethoxypropionate; aromatic organic solvents such as anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethylbenzene, diethylbenzene, pentylbenzene, isopropylbenzene, toluene, xylene, cymene, and mesitylene; and dimethyl sulfoxide (DMSO).

In the resist composition of the present embodiment, the (S) component may be used alone or as a mixed solvent of two or more types. Among them, PGMEA, PGME, γ-butyrolactone, EL, and cyclohexanone are preferable.

In addition, as the (S) component, a mixed solvent of PGMEA and a polar solvent is also preferable. The mixing ratio (mass ratio) may be appropriately determined by considering the compatibility of PGMEA and the polar solvent, etc., and is preferably within the range of 1:9 to 9:1, more preferably within the range of 2:8 to 8:2.

More specifically, when blending EL or cyclohexanone as a polar solvent, the mass ratio of PGMEA: EL or cyclohexanone is preferably 1:9 to 9:1, more preferably 2:8 to 8:2. In addition, when blending PGME as a polar solvent, the mass ratio of PGMEA: PGME is preferably 1:9 to 9:1, more preferably 2:8 to 8:2, and even more preferably 3:7 to 7:3. In addition, a mixed solvent of PGMEA, PGME, and cyclohexanone is also preferable.

In addition, as the (S) component, a mixed solvent of at least one selected from PGMEA and EL and γ-butyrolactone is also preferable. In this case, the mass ratio of the former and the latter is preferably 70:30 to 95:5 as the mixing ratio.

The amount of the (S) component to be used is not particularly limited, and is appropriately set according to the coating film thickness at a concentration that can be applied to a substrate, etc. Generally, the (S) component is used so that the solid content concentration of the resist composition is within the range of 0.1 to 20 mass%, preferably 0.2 to 15 mass%.

The resist composition of the present embodiment may be used to remove impurities, etc., after dissolving the resist material in the (S) component, using a polyimide porous film, a polyamideimide porous film, or the like. For example, the resist composition may be filtered using a filter made of a polyimide porous film, a filter made of a polyamideimide porous film, a filter made of a polyimide porous film and a polyamideimide porous film, or the like. Examples of the polyimide porous film and the polyamideimide porous film include those described in Japanese Patent Laid-Open No. 2016-155121.

The resist composition of the present embodiment described above contains a resin component (A1) having the above-described structural unit (a01).

The constituent unit (a01) has an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms. Since the constituent unit (a01) has iodine atoms, it has high absorption efficiency of EUV (extreme ultraviolet) and EB (electron beam).

In addition, the constituent unit (a01) has a divalent linking group in the side chain. Therefore, the resin component (A1) having the constituent unit (a01) has a different three-dimensional structure and has higher solubility in a developing solution compared to a resin component having a constituent unit that does not have a divalent linking group in the side chain.

Therefore, it is presumed that the resist composition of the present embodiment containing the resin component (A1) can achieve high sensitivity and form a resist pattern with good roughness reduction.

(Method of forming a resist pattern)

A method for forming a resist pattern according to a second aspect of the present invention is a method comprising the steps of forming a resist film on a support using the resist composition according to the first aspect of the present invention described above, exposing the resist film, and developing the exposed resist film to form a resist pattern.

As one embodiment of such a resist pattern forming method, for example, a resist pattern forming method performed as follows can be exemplified.

First, the resist composition of the embodiment described above is applied onto a support using a spinner or the like, and a bake (post-apply bake (PAB)) treatment is performed, for example, at a temperature of 80 to 150° C. for 40 to 120 seconds, preferably 60 to 90 seconds, to form a resist film.

Next, selective exposure is performed on the resist film, for example, using an exposure device such as an electron beam lithography device or an ArF exposure device, by exposure via a mask (mask pattern) on which a predetermined pattern is formed, or by lithography via direct irradiation of an electron beam without intervening the mask pattern, and then baking (post-exposure bake (PEB)) treatment is performed, for example, at a temperature condition of 80 to 150°C for 40 to 120 seconds, preferably 60 to 90 seconds.

Next, the resist film is developed. In the case of an alkaline developing process, the developing process is performed using an alkaline developer, and in the case of a solvent developing process, a developer containing an organic solvent (organic developer) is used.

After the development process, a rinsing process is preferably performed. In the case of an alkaline development process, a water rinse using pure water is preferable, and in the case of a solvent development process, a rinsing solution containing an organic solvent is preferably used.

In the case of a solvent development process, after the development treatment or rinsing treatment, a treatment may be performed to remove the developer or rinsing solution attached to the pattern using a supercritical fluid.

After developing or rinsing, drying is performed. In addition, in some cases, baking (post-bake) may be performed after the developing treatment.

In this way, a resist pattern can be formed.

As the support, there is no particular limitation, and a conventionally known one can be used, for example, a substrate for electronic components, or a substrate having a predetermined wiring pattern formed thereon, etc. More specifically, a silicon wafer, a metal substrate such as copper, chromium, iron, or aluminum, a glass substrate, etc. can be used. As the material for the wiring pattern, for example, copper, aluminum, nickel, or gold can be used.

The wavelength used for exposure is not particularly limited, and can be performed using radiation such as an ArF excimer laser, a KrF excimer laser, an F ₂ excimer laser, EUV (extreme ultraviolet), VUV (vacuum ultraviolet), EB (electron beam), X-ray, or soft X-ray. The resist composition has high usability as a KrF excimer laser, an ArF excimer laser, EB or EUV, has even higher usability as an ArF excimer laser, EB or EUV, and has particularly high usability as an EB or EUV. That is, the method for forming a resist pattern of the present embodiment is a particularly useful method when the step of exposing the resist film includes an operation of exposing the resist film with EUV (extreme ultraviolet) or EB (electron beam).

The exposure method of the resist film may be conventional exposure (dry exposure) performed in an inert gas such as air or nitrogen, or liquid immersion lithography.

Immersion exposure is an exposure method in which the space between the resist film and the lowest lens of the exposure device is filled with a solvent (immersion medium) having a refractive index higher than that of air, and exposure (immersion exposure) is performed in that state.

As the immersion medium, a solvent having a refractive index greater than that of air and smaller than that of the resist film to be exposed is preferable, and examples thereof include water, a fluorine-based inert liquid, a silicone-based solvent, and a hydrocarbon-based solvent.

As an immersion medium, water is preferably used.

As an alkaline developer used for developing in an alkaline developing process, an example thereof is a 0.1 to 10 mass% tetramethylammonium hydroxide (TMAH) aqueous solution.

In the solvent development process, the organic solvent contained in the organic developer used for the development treatment may be any organic solvent capable of dissolving component (A) (component (A) before exposure), and may be appropriately selected from known organic solvents. Specifically, polar solvents such as ketone solvents, ester solvents, alcohol solvents, nitrile solvents, amide solvents, and ether solvents, and hydrocarbon solvents, etc., may be mentioned.

Examples of ester solvents include methyl acetate, butyl acetate, ethyl acetate, isopropyl acetate, pentyl acetate, isopentyl acetate, amyl acetate, propylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, ethyl-3-ethoxypropionate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl formate, ethyl formate, butyl formate, propyl formate, ethyl lactate, butyl lactate, propyl lactate, butyl butanoate, methyl 2-hydroxyisobutyrate, isoamyl acetate, isobutyl isobutyrate, and butyl propionate.

Examples of nitrile solvents include acetonitrile, propionitrile, valeronitrile, and butyronitrile.

In the organic developer, known additives can be mixed as needed. Examples of the additives include surfactants. The surfactants are not particularly limited, but examples thereof include ionic or nonionic fluorine-based and/or silicone-based surfactants. As the surfactant, a nonionic surfactant is preferable, and a nonionic fluorine-based surfactant or a nonionic silicone-based surfactant is more preferable.

When blending a surfactant, the blending amount is usually 0.001 to 5 mass%, preferably 0.005 to 2 mass%, and more preferably 0.01 to 0.5 mass%, relative to the total amount of the organic developer.

The developing process can be carried out by a known developing method, and examples thereof include a method of immersing a support in a developing solution for a certain period of time (dip method), a method of building up a developing solution on the surface of a support by surface tension and leaving it stationary for a certain period of time (puddle method), a method of spraying a developing solution on the surface of a support (spray method), and a method of continuously dispensing a developing solution while scanning a developer dispensing nozzle at a certain speed on a support rotating at a certain speed (dynamic dispensing method).

As the organic solvent contained in the rinse solution used for the rinse treatment after the development treatment in the solvent development process, for example, among the organic solvents exemplified as organic solvents used in the above organic developer, one which is difficult to dissolve the resist pattern can be appropriately selected and used. Usually, at least one type of solvent selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, an amide solvent, and an ether solvent is used. Among these, at least one type selected from a hydrocarbon solvent, a ketone solvent, an ester solvent, an alcohol solvent, and an amide solvent is preferable, at least one type selected from an alcohol solvent and an ester solvent is more preferable, and an alcohol solvent is particularly preferable.

The alcohol solvent used in the rinse liquid is preferably a monohydric alcohol having 6 to 8 carbon atoms, and the monohydric alcohol may be linear, branched, or cyclic. Specifically, examples thereof include 1-hexanol, 1-heptanol, 1-octanol, 2-hexanol, 2-heptanol, 2-octanol, 3-hexanol, 3-heptanol, 3-octanol, 4-octanol, and benzyl alcohol. Among these, 1-hexanol, 2-heptanol, and 2-hexanol are preferable, and 1-hexanol and 2-hexanol are more preferable.

These organic solvents may be used alone or in combination of two or more. In addition, they may be used in combination with organic solvents other than those mentioned above or with water. However, considering the development characteristics, the amount of water in the rinse solution is preferably 30 mass% or less, more preferably 10 mass% or less, still more preferably 5 mass% or less, and particularly preferably 3 mass% or less, relative to the total amount of the rinse solution.

The rinse solution may contain known additives as needed. Examples of such additives include surfactants. Surfactants include the same surfactants as those described above, and nonionic surfactants are preferred, and nonionic fluorine-based surfactants or nonionic silicone-based surfactants are more preferred.

When blending a surfactant, the blending amount is usually 0.001 to 5 mass%, preferably 0.005 to 2 mass%, and more preferably 0.01 to 0.5 mass%, relative to the total amount of the rinse liquid.

The rinsing treatment (cleaning treatment) using the rinsing liquid can be performed by a known rinsing method. Examples of the rinsing treatment method include a method of continuously drawing out the rinsing liquid onto a support rotating at a constant speed (rotary application method), a method of immersing the support in the rinsing liquid for a constant period of time (dip method), and a method of spraying the rinsing liquid onto the surface of the support (spray method).

According to the resist pattern forming method of the present embodiment described above, since the resist composition described above is used, high sensitivity can be achieved and a resist pattern having good roughness reduction can be formed.

It is preferable that the resist composition of the embodiment described above, and the various materials (for example, a resist solvent, a developer, a rinse solution, an anti-reflection film forming composition, a topcoat forming composition, etc.) used in the pattern forming method of the embodiment described above do not contain impurities such as metals, metal salts containing halogens, acids, alkalis, components containing sulfur atoms or phosphorus atoms, etc. Here, examples of the impurities containing metal atoms include Na, K, Ca, Fe, Cu, Mn, Mg, Al, Cr, Ni, Zn, Ag, Sn, Pb, Li, or salts thereof. The content of the impurities contained in these materials is preferably 200 ppb or less, more preferably 1 ppb or less, still more preferably 100 ppt (parts per trillion) or less, particularly preferably 10 ppt or less, and most preferably substantially free of impurities (below the detection limit of a measuring device).

(compound)

A compound related to the third aspect of the present invention is a compound represented by the following general formula (a0-1).

[Chemical formula 63]

[In the formula, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰¹ is a divalent linking group. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced by iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced by iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.]

The compound represented by the general formula (a0-1) of the present embodiment is the same as the compound represented by the general formula (a0-1) in the resist composition related to the first aspect of the present invention.

The compound of the present embodiment is preferably a compound represented by the following general formula (a0-1-1).

[Chemical formula 64]

[Wherein, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰⁰¹ is a divalent linking group having an ester bond, an aromatic hydrocarbon group, a lactone-containing cyclic group, or a group consisting of a combination of these. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.]

The compound represented by the general formula (a0-1-1) of the present embodiment is the same as the compound represented by the general formula (a0-1-1) in the resist composition related to the first aspect of the present invention.

(Method for producing a compound)

The compound of the present embodiment can be produced, for example, by an esterification reaction between a compound represented by the following general formula (C0-1) and a compound represented by the following general formula (AL0-1).

[Chemical formula 65]

[In the formula, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰¹ is a divalent linking group. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced by iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced by iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.]

The temperature conditions of the above esterification reaction are not particularly limited, and are, for example, about -10 to 120°C.

The reaction time of the above esterification reaction is not particularly limited, and is, for example, about 1 to 72 hours.

Examples of the reaction solvent used in the above esterification reaction include dichloromethane, dichloroethane, chloroform, tetrahydrofuran, N,N-dimethylformamide, acetonitrile, propionitrile, N,N'-dimethylacetamide, dimethyl sulfoxide, etc.

Additionally, in the above esterification reaction, a condensing agent and a basic catalyst may be used.

As condensing agents, specific examples thereof include N,N'-dicyclohexylcarbodiimide, N,N'-diisopropylcarbodiimide, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and carbonyldiimidazole (CDI).

Examples of the basic catalyst include, specifically, tertiary amines such as trimethylamine, triethylamine, and tributylamine; aromatic amines such as pyridine, dimethylaminopyridine (DMAP), and pyrrolidinopyridine; diazabicyclononene (DBN), and diazabicycloundecene (DBU).

The compound represented by the above general formula (C0-1) may be a carboxylic acid chloride in order to improve the electron-seeking property and increase the reactivity. That is, the hydroxyl group in the compound represented by the above general formula (C0-1) may be replaced with a chlorine atom.

After the reaction is completed, the compound represented by the general formula (a0-1) in the reaction solution may be isolated and purified.

For isolation and purification, conventionally known methods can be used, and for example, concentration, solvent extraction, distillation, crystallization, recrystallization, chromatography, etc. can be used alone or in combination of two or more of these.

The structure of the compound obtained as described above can be confirmed by general organic analysis methods such as ^1H -nuclear magnetic resonance (NMR) spectroscopy, ^13C -NMR spectroscopy, ^19F -NMR spectroscopy, infrared absorption (IR) spectroscopy, mass spectrometry (MS), elemental analysis, and X-ray crystal diffraction.

＜Synthesis of a compound represented by the general formula (AL0-1)＞

The compound represented by the above formula (AL0-1) may be a commercially available product or may be synthesized.

For example, as shown below, a compound represented by the above formula (AL0-1) may be synthesized by a Grignard reaction in which a ketone represented by the following general formula (AL0-1pre) is reacted with an organic magnesium halide represented by ^Ra02MgBr .

[Chemical formula 66]

[In the formula, Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.]

As the reaction solvent used in the above Grignard reaction, the same reaction solvent as used in the above esterification reaction can be mentioned.

The temperature conditions of the above Grignard reaction are not particularly limited, and are, for example, about -10 to 120°C.

The reaction time of the above Grignard reaction is not particularly limited, and is, for example, about 1 to 72 hours.

In addition, the compound represented by the above formula (AL0-1) can also be synthesized by a nucleophilic addition reaction between an aromatic compound having an iodine atom and a ketone in the presence of a strong base (such as potassium hexamethyldisilazide (KHMDS)).

In addition, a compound represented by the above formula (AL0-1) may be synthesized by reacting the compound represented by the above formula (AL0-1) with another compound, which is different from the compound.

For example, a compound represented by the above formula (AL0-1) may be synthesized by reacting 5-norbornene-2,3-dicarboxylic anhydride with a compound represented by the following general formula (AL0-1').

[Chemical formula 67]

[In the formula, Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.]

The compound of the present embodiment described above is useful for producing a resin related to the fourth aspect described below.

The fourth aspect of the present invention is a resin having a structural unit derived from a compound represented by the general formula (a0-1).

The resin related to the fourth aspect of the present invention is the same as the component (A1) described above.

The resin related to the fourth aspect of the present invention is a resin useful in a resist composition.

Example

Hereinafter, the present invention will be described in more detail by examples, but the present invention is not limited to these examples.

＜Examples of compound synthesis＞

[Example of synthesis of intermediates]

· Synthesis of intermediate AL-1

4-Iodoacetophenone (AC-1) (20 g) was dissolved in THF (80 g), and methylmagnesium bromide (THF solution, 1.0 mol/L) (200 mL) was added dropwise at 0°C or lower, and the mixture was stirred for 2 hours. Then, 100 g of saturated ammonium chloride was added to stop the reaction, and extraction was performed with 200 g of ethyl acetate. The solvent in the obtained organic layer was distilled off, and the residue was purified by silica gel chromatography to obtain intermediate AL-1.

[Chemical formula 68]

· Synthesis of intermediate AL-2

Intermediate AL-2 was obtained by the same manufacturing method as intermediate AL-1, except that the methyl magnesium bromide solution was changed to an equimolar ethynyl magnesium bromide solution.

[Chemical formula 69]

· Synthesis of intermediate AL-3

2-Iodothiophene (AC-2), 25 g, was added to a flask, dissolved in 150 g of THF, and 0.6 M KHMDS toluene solution (240.7 g) was added dropwise at -30 °C or lower, and stirred at 0 °C or lower for 30 minutes. Then, acetone (10.0 g) was added dropwise at 0 °C or lower, and stirred for 3 hours. Thereafter, 100 g of a saturated ammonium chloride aqueous solution was added dropwise, the reaction was stopped, and extraction was performed with ethyl acetate (200 g). Thereafter, the solvent was distilled off, and the residue was purified by silica gel chromatography to obtain intermediate AL-3.

[Chemical formula 70]

· Synthesis of intermediate AL-4

2,4,6-Triiodoacetophenone (AC-3) (20 g) was dissolved in THF (120 g), and 80 mL of methylmagnesium bromide (THF solution, 1.0 mol/L) was added dropwise at 0°C or lower, and the mixture was stirred for 2 hours. Then, 100 g of saturated ammonium chloride was added to stop the reaction, and extraction was performed with 200 g of ethyl acetate. The solvent in the obtained organic layer was distilled off, and the residue was purified by silica gel chromatography to obtain intermediate AL-4.

[Chemical formula 71]

· Synthesis of intermediate AL-5

AL-5 was obtained by the same manufacturing method as AL-4, except that the methyl magnesium bromide solution was changed to an equimolar vinyl magnesium bromide solution.

[Chemical formula 72]

· Synthesis of intermediate AL-6

5-Norbornene-2,3-dicarboxylic anhydride (20 g) was placed in a 3-necked flask, THF (200 g) was added, and dissolved. Next, AL-1 (35 g) and NaH (3.5 g) were added, and the mixture was stirred at room temperature for 4 hours. Next, a saturated aqueous ammonium chloride solution (200 g) was added to terminate the reaction. Next, extraction was performed with 400 g of ethyl acetate, and the organic solvent was distilled off. The obtained concentrate was dissolved in 300 g of ethyl acetate, acetone (35 g), sodium bicarbonate (19 g), and Oxone (90 g) were added, and the mixture was stirred for 8 hours. 300 g of pure water was added to the reaction solution to stop the reaction, 120 g of ethyl acetate was added to perform extraction, and the solvent was distilled off. The obtained concentrate was purified by silica gel column chromatography to obtain intermediate AL-6.

[Chemical formula 73]

· Synthesis of intermediate AL-7

AL-7 was obtained by the same manufacturing method as AL-6, except that 5-norbornene-2,3-dicarboxylic anhydride was replaced with equimolar amounts of exo-3,6-epoxy-1,2,3,6-tetrahydrophthalic anhydride.

[Chemical formula 74]

[Synthesis example of compound (a0-01-1)]

Intermediate AL-1 (25 g) was added to a flask and dissolved in dichloromethane (250 g). Then, glycolic acid methacrylate (19 g), triethylamine (18 g) and DMAP (650 mg) were added, followed by dropwise addition of diisopropylcarbodiimide (21 g) and stirring for 4 hours. The reaction solution was filtered, and the filtrate was washed with 1% hydrochloric acid and pure water, and the organic solvent was distilled off, and the residue was purified by silica gel chromatography to obtain compound (a0-01-1).

[Chemical formula 75]

The obtained compound (a0-01-1) was subjected to NMR measurement (CDCl ₃ ), and its structure was identified from the results below.

[Synthesis example of compound (a0-01-2)]

Compound (a0-01-2) was obtained by the same manufacturing method as for compound (a0-01-1) except that glycolic acid methacrylate was changed to equimolar 4-vinylbenzoic acid.

[Chemical formula 76]

The obtained compound (a0-01-2) was subjected to NMR measurement (CDCl ₃ ), and its structure was identified from the results below.

[Synthesis example of compound (a0-01-3)]

Intermediate AL-6 (25 g) was dissolved in 250 g of THF, cooled to 0°C, and triethylamine (9 g) and methacrylic acid chloride (8 g) were added dropwise. The mixture was returned to room temperature and stirred for 5 hours, after which a 5% aqueous sodium bicarbonate solution (50 g) was added to stop the reaction, and extraction was performed with t-butyl methyl ether (150 g). The solvent in the obtained organic layer was distilled off, and the residue was purified by silica gel chromatography to obtain compound (a0-01-3).

[Chemical formula 77]

The obtained compound (a0-01-3) was subjected to NMR measurement (CDCl ₃ ), and its structure was identified from the results below.

[Synthesis example of compound (a0-01-4)]

Compound (a0-01-4) was obtained by the same manufacturing method as compound (a0-01-2), except that intermediate AL-1 was changed to equimolar intermediate AL-2.

[Chemical formula 78]

The obtained compound (a0-01-4) was subjected to NMR measurement (CDCl ₃ ), and its structure was identified from the results below.

[Synthesis example of compound (a0-01-5)]

Compound (a0-01-5) was obtained by the same manufacturing method as for compound (a0-01-2), except that intermediate AL-1 was changed to equimolar intermediate AL-3.

[Chemical formula 79]

The obtained compound (a0-01-5) was subjected to NMR measurement (CDCl ₃ ), and its structure was identified from the following results.

[Synthesis example of compound (a0-01-6)]

AL-1 (25 g) was added to a flask, dissolved with dichloromethane (250 g), then 5-vinylsalicylic acid (15 g), CDI (17 g), and DBU (13 g) were added, and stirred for 6 hours. Subsequently, 1% citric acid (200 g) was added to the reaction solution to stop the reaction, and the organic layer was extracted and washed with pure water. After distilling off the organic solvent, the compound (a0-01-6) was obtained by purifying by silica gel column chromatography.

[Chemical formula 80]

The obtained compound (a0-01-6) was subjected to NMR measurement (CDCl ₃ ), and its structure was identified from the results below.

[Synthesis example of compound (a0-01-7)]

Compound (a0-01-7) was obtained by the same manufacturing method as for compound (a0-01-3), except that intermediate AL-6 was changed to equimolar intermediate AL-7.

[Chemical formula 81]

The obtained compound (a0-01-7) was subjected to NMR measurement (CDCl ₃ ), and its structure was identified from the results below.

[Synthesis example of compound (a0-01-8)]

Compound (a0-01-8) was obtained by the same manufacturing method as for compound (a0-01-6), except that intermediate AL-1 was changed to equimolar intermediate AL-4.

[Chemical formula 82]

The obtained compound (a0-01-8) was subjected to NMR measurement (CDCl ₃ ), and its structure was identified from the results below.

[Synthesis example of compound (a0-01-9)]

Compound (a0-01-9) was obtained by the same manufacturing method as for compound (a0-01-6), except that intermediate AL-1 was changed to equimolar intermediate AL-5.

[Chemical formula 83]

The obtained compound (a0-01-9) was subjected to NMR measurement (CDCl ₃ ), and its structure was identified from the results below.

＜Synthesis example 1 of polymer compound＞

[Synthesis example of polymer compound (A1-1)]

A dropping solution was prepared by dissolving 32.4 g of compound (a0-01-1), 10.0 g of compound (m-a10-1pre), and 2.38 g of azobis(isobutyric acid)dimethyl (V-601) as a polymerization initiator in 20.3 g of MEK (methyl ethyl ketone). 33.7 g of MEK was added to a three-necked flask connected to a thermometer, a reflux tube, and a nitrogen inlet tube, heated to 85°C under a nitrogen atmosphere, and the dropping solution was dropped over 4 hours. After completion of the dropping, the reaction solution was stirred at 85°C for 1 hour. Thereafter, the reaction solution was cooled to room temperature. After completion of the reaction, the obtained reaction solution was precipitated in 2,600 g of heptane and washed. The obtained white solid was filtered and dried under reduced pressure overnight, thereby obtaining the target polymer compound (A1-1).

[Chemical formula 84]

＜Synthesis examples of polymer compounds 2 to 15＞

Using the same method as in Synthesis Example 1 of a polymer compound, compounds (a0-01-1) to (a0-01-9) shown above, compounds (m-a10-1pre) to (m-a10-3pre), and (m-a2-1) to (m-a2-3) shown below were used to synthesize polymer compounds (A1-2) to (A1-15).

[Chemical formula 85]

For each obtained polymer compound, the weight average molecular weight (Mw) and molecular weight dispersity (Mw/Mn) were obtained by GPC measurement (converted to standard polystyrene).

In addition, for each obtained polymer compound, the copolymer composition ratio (the ratio (molar ratio) of each constituent unit in the structural formula) was obtained by carbon 13 nuclear magnetic resonance spectrum (600 MHz_ ¹³ C-NMR).

[Chemical formula 86]

Polymer compound (A1-1): Weight average molecular weight (Mw) 7500, molecular weight dispersion (Mw/Mn) 1.65, l/m ＝ 50/50.

Polymer compound (A1-2): Weight average molecular weight (Mw) 7400, molecular weight dispersion (Mw/Mn) 1.67, l/m ＝ 50/50.

Polymer compound (A1-3): Weight average molecular weight (Mw) 7500, molecular weight dispersion (Mw/Mn) 1.64, l/m ＝ 50/50.

Polymer compound (A1-4): Weight average molecular weight (Mw) 7600, molecular weight dispersion (Mw/Mn) 1.65, l/m ＝ 50/50.

Polymer compound (A1-5): Weight average molecular weight (Mw) 7400, molecular weight dispersion (Mw/Mn) 1.63, l/m ＝ 50/50.

Polymer compound (A1-6): Weight average molecular weight (Mw) 7500, molecular weight dispersion (Mw/Mn) 1.65, l/m ＝ 50/50.

[Chemical formula 87]

Polymer compound (A1-7): Weight average molecular weight (Mw) 7500, molecular weight dispersion (Mw/Mn) 1.64, l/m ＝ 50/50.

Polymer compound (A1-8): Weight average molecular weight (Mw) 7600, molecular weight dispersion (Mw/Mn) 1.67, l/m ＝ 50/50.

Polymer compound (A1-9): Weight average molecular weight (Mw) 7400, molecular weight dispersion (Mw/Mn) 1.66, l/m ＝ 50/50.

Polymer compound (A1-10): Weight average molecular weight (Mw) 7400, molecular weight dispersion (Mw/Mn) 1.67, l/m ＝ 50/50.

Polymer compound (A1-11): Weight average molecular weight (Mw) 7600, molecular weight dispersion (Mw/Mn) 1.63, l/m/n = 50/40/10.

[Chemical formula 88]

Polymer compound (A1-12): Weight average molecular weight (Mw) 7500, molecular weight dispersion (Mw/Mn) 1.66, l/m/n = 50/40/10.

Polymer compound (A1-13): Weight average molecular weight (Mw) 7500, molecular weight dispersion (Mw/Mn) 1.66, l/m/n = 50/40/10.

Polymer compound (A1-14): Weight average molecular weight (Mw) 7500, molecular weight dispersion (Mw/Mn) 1.67, l/m/n = 50/40/10.

Polymer compound (A1-15): Weight average molecular weight (Mw) 7400, molecular weight dispersion (Mw/Mn) 1.66, l/m/n = 50/40/10.

＜Preparation of a resist composition＞

(Examples 1 to 17, Comparative Examples 1 to 4)

Each component shown in Tables 1 to 3 was mixed and dissolved to prepare a resist composition for each example.

In Tables 1 to 3, each abbreviation has the following meaning. The numerical value in [ ] is the mixing amount (mass part).

(A1)-1 ∼ (A1)-15: The polymer compounds described above (A1-1) ∼ (A1-15).

(A2)-1: A polymer compound represented by the following chemical formula (A2-1). For this polymer compound (A2)-1, the weight average molecular weight (Mw) converted to standard polystyrene as determined by GPC measurement is 7500, and the molecular weight dispersion (Mw/Mn) is 1.64. The copolymerization composition ratio (the ratio (molar ratio) of each constituent unit in the structural formula) determined by ^13C -NMR is l/m = 50/50.

(A2)-2: A polymer compound represented by the following chemical formula (A2-2). For this polymer compound (A2)-2, the weight average molecular weight (Mw) converted to standard polystyrene as determined by GPC measurement is 7400, and the molecular weight dispersion (Mw/Mn) is 1.65. The copolymerization composition ratio (the ratio (molar ratio) of each constituent unit in the structural formula) determined by ^13C -NMR is l/m = 50/50.

(A2)-3: A polymer compound represented by the following chemical formula (A2-3). For this polymer compound (A2)-3, the weight average molecular weight (Mw) converted to standard polystyrene as determined by GPC measurement is 7600, and the molecular weight dispersity (Mw/Mn) is 1.68. The copolymerization composition ratio (the ratio (molar ratio) of each constituent unit in the structural formula) determined by ^13C -NMR is l/m/n/o = 38/46/11/5.

(A2)-4: A polymer compound represented by the following chemical formula (A2-4). For this polymer compound (A2)-4, the weight average molecular weight (Mw) converted to standard polystyrene as determined by GPC measurement is 7400, and the molecular weight dispersion (Mw/Mn) is 1.67. The copolymerization composition ratio (the ratio (molar ratio) of each constituent unit in the structural formula) determined by ^13C -NMR is l/m = 50/50.

[Chemical formula 89]

(B)-1: An acid generator comprising the following compound (B-1).

(B)-2: An acid generator comprising the following compound (B-2).

(D)-1: An acid diffusion control agent comprising the following compound (D-1).

(S)-1: Mixed solvent of propylene glycol monomethyl ether acetate/propylene glycol monomethyl ether = 60/40 (mass ratio).

[Chemical formula 90]

＜Formation of the registration pattern＞

Each resist composition of each example was applied using a spinner onto an 8-inch silicon substrate treated with hexamethyldisilazane (HMDS), prebaked (PAB) on a hot plate at a temperature of 110° C. for 60 seconds, and dried to form a resist film having a film thickness of 70 nm.

Next, for the resist film, an electron beam writing device JEOL-JBX-9300FS (manufactured by Nippon Electronics Co., Ltd.) was used to write (expose) a 1:1 line-and-space pattern (hereinafter referred to as LS pattern) with a line width of 50 nm at an acceleration voltage of 100 kV, and then a post-exposure baking (PEB) treatment was performed at 100°C for 60 seconds.

Next, alkaline development was performed for 60 seconds at 23°C using a 2.38 mass% tetramethylammonium hydroxide (TMAH) aqueous solution “NMD-3” (trade name, manufactured by Tokyo Ohka Kogyo Co., Ltd.).

Afterwards, a 15-second water rinse was performed using pure water.

As a result, a 1:1 LS pattern with a line width of 50 nm was formed.

[Evaluation of optimal exposure dose (Eop)]

The optimal exposure dose Eop (μC/cm2) for forming a pattern of the target size by the above <Formation of a Resist Pattern> was obtained. This is shown as “Eop (μC/cm2)” in Tables 4 and 5.

[LWR Evaluation]

For the LS pattern formed in the above <Formation of a Resist Pattern>, 3σ, which is a measure representing LWR, was obtained. This is shown in Tables 4 and 5 as “LWR (nm).”

"3σ" is expressed as "LWR" (unit: nm) as three times the standard deviation (σ) obtained from the measurement results obtained by measuring the line positions at 400 points in the longitudinal direction of the line using a scanning electron microscope (acceleration voltage 800 V, product name: S-9380, manufactured by Hitachi High-Technologies Co., Ltd.). A smaller value of 3σ means that the roughness of the line side wall is smaller, and an LS pattern with a more uniform width is obtained.

As shown in Tables 4 and 5, it was confirmed that the resist composition of the example had a higher sensitivity in resist pattern formation and a better LWR than the resist composition of the comparative example.

Above, although the preferred embodiments of the present invention have been described, the present invention is not limited to these embodiments. Addition, omission, substitution, and other changes in the configuration are possible without departing from the scope of the present invention. The present invention is not limited by the above description, but is limited only by the scope of the appended claims.

Claims (7)

A resist composition that generates acid upon exposure and also changes its solubility in a developer solution by the action of the acid.
A resist composition containing a resin component (A1) having a structural unit (a01) derived from a compound represented by the following general formula (a0-1).

[In the formula, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰¹ is a divalent linking group. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.] In paragraph 1,
A resist composition, wherein the proportion of the structural unit (a01) in the resin component (A1) is 20 to 80 mol% with respect to the total (100 mol%) of the entire structural units constituting the resin component (A1). In claim 1 or 2,
A resist composition, wherein the above-mentioned structural unit (a01) is a structural unit (a011) derived from a compound represented by the following general formula (a0-1-1).

[Wherein, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰⁰¹ is a divalent linking group having an ester bond, an aromatic hydrocarbon group, a lactone-containing cyclic group, or a group consisting of a combination of these. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.] A method for forming a resist pattern, comprising the steps of: forming a resist film on a support using the resist composition described in claim 1 or claim 2; exposing the resist film; and developing the exposed resist film to form a resist pattern. In paragraph 4,
A method for forming a resist pattern, wherein in the process of exposing the resist film, the resist film is exposed to EUV (extreme ultraviolet) or EB (electron beam). A compound represented by the following general formula (a0-1).

[In the formula, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰¹ is a divalent linking group. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.] A compound represented by the following general formula (a0-1-1).

[Wherein, R ⁰¹ is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or a halogenated alkyl group having 1 to 10 carbon atoms. L ⁰⁰¹ is a divalent linking group having an ester bond, an aromatic hydrocarbon group, a lactone-containing cyclic group, or a group consisting of a combination of these. Ra ⁰¹ and Ra ⁰² are each independently a hydrocarbon group which may have a substituent. Ar ⁰¹ is an aryl group in which some or all of the hydrogen atoms are replaced with iodine atoms, or a heteroaryl group in which some or all of the hydrogen atoms are replaced with iodine atoms. The aryl group and heteroaryl group may have a substituent other than an iodine atom.]